4.4 The General Options Menu

After you specified all data concerning the molecule you want to examine, you are on your way to the last of the four main menus. Before reaching it, you will perhaps get a message like the following:

DO YOU WANT TO DELETE DATA GROUPS LIKE
    $energy
    $grad
    $hessian
    $hessian (projected)
    $last energy change
    $maximum norm of internal gradient
    $dipgrad
    $vibrational normal modes
    $vibrational spectrum
    $cartesianforce interspace
LEFT OVER FROM PREVIOUS CALCULATIONS ? DEFAULT(n)

define has scanned your input file for this session and found some data groups which might have become obsolete. If they are still acceptable depends on the changes you made during your present define session. They are obviously incorrect if you changed the molecule under consideration; but any change in the basis sets or the occupation numbers will make them dangerous, too, because you might not know some day if they really refer to the basis set which is defined in this control file. As a rough guide, delete them whenever you have made changes in one of the first three main menus during your define session.

After that you will reach the last main menu of define which helps you to control the actions of all TURBOMOLE programs. The meanings of the various options are explained in more detail in the description of the individual programs, therefore only a short explanation will be given here.

Now have a look at the menu:

GENERAL MENU : SELECT YOUR TOPIC
scf    : SELECT NON-DEFAULT SCF PARAMETER
mp2    : OPTIONS AND DATA GROUPS FOR rimp2/mpgrad
cc     : OPTIONS AND DATA GROUPS FOR ricc2
pnocc  : OPTIONS AND DATA GROUPS FOR pnoccsd
dft    : DFT PAAMETERS
dsp    : DFT DISPERSION CORRECTIONS
ri     : RI PARAMETERS
rijk   : RI-JK-HF PARAMETERS
trunc  : USE TRUNCATED AUXBASIS DURING ITERATIONS
marij  : MULTIPOLE ACCELERATED RI-J
senex  : SEMINUMERICAL EXCHANGE PARAMETERS
hybno  : HYBRID NOGA/DIAG PARAMETERS
prop   : SELECT TOOLS FOR SCF-ORBITAL ANALYSIS
drv    : SELECT NON-DEFAULT INPUT PARAMETER FOR EVALUATION
         OF ANALYTICAL ENERGY DERIVATIVES
         (GRADIENTS, FORCE CONSTANTS)
rex    : SELECT OPTIONS FOR GEOMETRY UPDATES USING RELAX
stp    : SELECT NON-DEFAULT STRUCTURE OPTIMIZATION PARAMETER
ex     : EXCITED STATE AND RESPONSE OPTIONS
relham : OPTIONS FOR RELATIVISTIC HAMILTONIAN
e      : DEFINE EXTERNAL ELECTROSTATIC FIELD
b      : DEFINE EXTERNAL MAGNETIC FIELD
rirpa  : RIRPA PARAMETERS
gw     : OPTIONS AND DATA GROUPS FOR GW (escf)
nmr    : NMR SHIFT PARAMETERS
ncoup  : NMR COUPLING PARAMETERS
epr    : EPR PARAMETERS
fde    : FROZEN DENSITY EMBEDDING
dis    : DISPLAY MOLECULAR GEOMETRY
list   : LIST OF CONTROL FILE
&      : GO BACK TO OCCUPATION/ORBITAL ASSIGNMENT MENU
* or q : END OF DEFINE SESSION

This menu serves very different purposes. The next subsection deals with commands required to activate and/or specify specific methods of calculation. The subsequent subsection describes commands used to select non-default options. Standard SCF calculations do not require special action, just leave the menu. The final subsection describes the settings for property calculations.

4.4.1 Important commands

DFT calculations

Command dft leads you to the menu:

STATUS OF DFT_OPTIONS:
 DFT is NOT used
   functional b-p
     gridsize m3

 ENTER DFT-OPTION TO BE MODIFIED

 func: TO CHANGE TYPE OF FUNCTIONAL
 grid: TO CHANGE GRIDSIZE
  on:   TO SWITCH ON  DFT
 Just <ENTER>, q or '*' terminate this menu.

To activate DFT input on and then specify the grid for the quadrature of exchange-correlation terms. TURBOMOLE offers grids 1 (coarse) to 7 (finest), and the multiple grids m3 to m5 [8]. The latter employ a coarser grid during SCF iterations, and grid 3 to grid 5 in the final SCF iteration and the gradient evaluation. Default is grid m3, for clusters with more than 50 atoms use m4. Note that larger grids are required for relativistic all-electron calculaations. These are employed by appending a to the gridsize, e.g., 4a. For hybrid density functionals, the multiple grids do not result in a notable reduction of the computational costs and the standard grids are recommended. These are also recommended for response properties and parallel calculations, especially for magnetic properties such as NMR shifts and coupling constants. See also Sec. 8.

The functionals supported within define are obtained with the command func; the first part of the output looks like

 SURVEY OF AVAILABLE EXCHANGE-CORRELATION ENERGY FUNCTIONALS

 FUNCTIONAL      | TYPE | EXCHANGE       | CORRELATION    | REFERENCES
 ---------------------------------------------------------------------
 s-vwn           | LDA  | S              | VWN(V)         | 1-3
 s-vwn_Gaussian  | LDA  | S              | VWN(III)       | 1-3
 pwlda           | LDA  | S              | PW             | 1,2,4
 b-lyp           | GGA  | S+B88          | LYP            | 1,2,6
 b-vwn           | GGA  | S+B88          | VWN(V)         | 1-3,5
 b-p             | GGA  | S+B88          | VWN(V)+P86     | 1-3,5,7
 pbe             | GGA  | S+PBE(X)       | PW+PBE(C)      | 1,2,4,8
 tpss            | MGGA | S+TPSS(X)      | PW+TPSS(C)     | 1,2,4,14
 bh-lyp          | HYB  | 0.5(S+B88)     | LYP            | 1,2,5,6,9
                 |      | +0.5HF         |                |

This list is far from being complete. Especially with the inclusion of the XCFun and LibXC libraries, uncounted combinations of exchange and correlation functionals are available. To get an overview of further functionals and how to use arbitrary combinations and exact exchange portions, please read section 6.3.

Default is b-p, i.e. B-P86, which is probably best for the whole of Chemistry [52]. For main group compounds we recommend b3-lyp; note that GAUSSIAN uses partly different implementations [52].

The programs dscf and grad are used to carry out conventional DFT treatments, i.e. $J$ and $K$ are evaluated without approximations.

RI-J calculations

For non-hybrid functionals we strongly recommend the RI-$J$ procedure, which speeds up calculations by a factor 10 at least (as compared to conventional treatments) without sacrificing accuracy. Command ri gives:

STATUS OF RI-OPTIONS:
    RI IS NOT USED
    Memory for RI:           200 MB
    Filename for auxbasis: auxbasis

 ENTER RI-OPTION TO BE MODIFIED
      m: CHANGE MEMORY FOR RI
      f: CHANGE FILENAME
   jbas: ASSIGN AUXILIARY RI-J BASIS SETS
     on: TO SWITCH ON  RI
 Use <ENTER>, q, end, or * to leave this menu

Activate RI-$J$ with on, and choose with m the memory you can dedicate to store three-center integrals (Keyword: $ricore), default is 200 MB. The more memory, the faster the calculation.

A rough guide: put $ricore to about $2/3$ of the memory of the computer. Use OS specific commands (top on most UNIX systems), during an ridft run to find the actual memory usage and then adjust $ricore, the keyword in control specifying memory.

If the option jbas is selected, define enters a submenu which allows the assignment of auxiliary basis sets (for an explanation of the menu items see Section 4.2). Where available, the program will select by default the auxiliary basis sets optimized for the orbital basis used. Please note that treatment of systems with diffuse wavefunctions may also require an extension of the auxiliary basis. For this cases enlarge the sets of s- and p-functions with diffuse functions.

The RI-$J$ option is only supported by programs ridft and rdgrad, if you use jobex to optimize molecular geometry, put: nohup jobex -ri ...

MARI-J option

RI-$J$ calculations can be done even more efficiently with the Multipole Accelerated RI-J (MARI-J) option, especially for larger molecules where almost linear scaling is achieved [53].

Parameters:
 1) precision parameter:               1.00E-06
 2) maximum multipole l-moment:              10
 3) maximum number of bins:                   8
 4) minimum separation of bins:            0.00
 5) maximum allowed extension:            20.00
 6) threshold for multipole neglect:   1.00E-18

Enter the number to change a value or <return> to accept all.

Just rely on the defaults.

Multiple auxiliary basis sets

With the command trunc you can switch on this option. Effect: a reduced auxiliary (or fitting) basis to represent the electron density is employed during SCF iterations, the final SCF iteration and the gradient are computed with the full auxiliary basis.

 truncated RI ALREADY SWITCHED ON
 DO YOU WANT TO SWITCH OFF truncation ? (default=no)

Note: trunc is presently not compatible with marij!

RI in SCF calculations

Considerable savings in CPU times are achieved with the RI technique for both Coulomb $J$ and exchange $K$ terms in SCF calculations, the RI-JK method [54], provided large basis sets are employed, e.g. TZVPP, cc-pVTZ, or cc-pVQZ. With rijk you get:

STATUS OF RI-OPTIONS:
    RI IS NOT USED
    Memory for RI:           200 MB
    Filename for auxbasis: auxbasis

 ENTER RI-OPTION TO BE MODIFIED
      m: CHANGE MEMORY FOR RI
      f: CHANGE FILENAME
  jkbas: ASSIGN AUXILIARY RI-JK BASIS SETS
     on: TO SWITCH ON  RI
 Use <ENTER>, q, end, or * to leave this menu

For an explanation of the menu items see Section 4.4. RI-JK calculations can be carried out with the program ridft.

Optimization to minima and transition structures using Statpt

Structure optimizations can be carried out by the program statpt. For minimizations no additional keywords are required. The default values are assumed, which work in most of the cases. Structure optimization is performed in internal coordinates if they have been set. Otherwise, Cartesian coordinates are used. One can switch the optimization in internal coordinates on or off, respectively in internal redundant or Cartesian coordinates. For transition structure optimizations the index of transition vector has to be set to an integer value $>$ 0 (0 means structure minimization). The value of the index specifies transition vector to follow during the saddle point search. Note, that Hessian eigenpairs are stored in ascending order of the eigenvalues, i.e. the eigenpair with the smallest eigenvector has the index 1.
The command stp gives:

 ------------------------------------------------------------------------
 CONVERGENCE CRITERIA:

 thre  1.000000E-06     thre : threshold for ENERGY CHANGE
 thrd  1.000000E-03     thrd : threshold for MAX. DISPL. ELEMENT
 thrg  1.000000E-03     thrg : threshold for MAX. GRAD. ELEMENT
 rmsd  5.000000E-04     rmsd : threshold for RMS OF DISPL.
 rmsg  5.000000E-04     rmsg : threshold for RMS OF GRAD.

 defl : set default values.

 ------------------------------------------------------------------------

 OPTIMIZATION refers to

 int   off         int: INTERNAL coordinates
 rdn   off         rdn: REDUNDANT INTERNAL coordinates
 crt   on          crt: CARTESIAN coordinates
 NOTE : options int and crt exclude each other

 ENTER STATPT-OPTIONS TO BE MODIFIED

 itvc    0              itvc : change INDEX OF TRANSITION VECTOR
 updte   bfgs           updte: change method of HESSIAN UPDATE
 hsfrq   0              hsfrq: frequency of HESSIAN CALCULATION
 kptm    0              kptm : FREEZING transition vector INDEX
 hdiag 5.000000E-01     hdiag: change DIAGONAL HESSIAN ELEMENTS
 rmax  3.000000E-01     rmax : change MAX. TRUST RADIUS
 rmin  1.000000E-04     rmin : change MIN. TRUST RADIUS
 trad  3.000000E-01     trad : change TRUST RADIUS
 ------------------------------------------------------------------------
 Just <ENTER>, q or '*' terminate this menu.

Excited states, frequency-dependent properties, and stability analysis

Excited state calculations with RPA or CIS (based on HF-SCF) and TDDFT procedures as well as stability analyses (SCF or DFT) are carried out by the program escf.

You will need a well converged HF-SCF or DFT calculation that were converged to at least $scfconv=7, see Section 4.4.2.

Details of calculations are specified with the command ex:

MAIN MENU FOR RESPONSE CALCULATIONS

OPTION | STATUS | DESCRIPTION
-------------------------------------------------------------------
rpas   | off    | RPA SINGLET EXCITATIONS (TDHF OR TDDFT)
ciss   | off    | TDA SINGLET EXCITATIONS (CI SINGLES)
rpat   | off    | RPA TRIPLET EXCITATIONS (TDHF OR TDDFT)
cist   | off    | TDA TRIPLET EXCITATIONS (CI SINGLES)
polly  | off    | STATIC POLARIZABILITY
dynpol | off    | DYNAMIC POLARIZABILITY
single | off    | SINGLET STABILITY ANALYSIS
triple | off    | TRIPLET STABILITY ANALYSIS
nonrel | off    | NON-REAL STABILITY ANALYSIS
bse    | off    | BETHE-SALPETER EX.
cbse   | off    | corr-aug. BETHE-SALPETER EX.

ENTER <OPTION> TO SWITCH ON/OFF OPTION, * OR q TO QUIT

If you have selected an option, e.g. rpas, and quit this menu, you will get another menu:

SELECT IRREP AND NUMBER OF STATES
ENTER ? FOR HELP, * OR Q TO QUIT, & TO GO BACK

This should be self-evident. The input of the excitations is used to estimate the memory requirements. The $GW$ method is available in a separate gw menu:

NO GW OPTIONS CURRENTLY SET
GW                     (gw on/off) : off
RI-GW                (rigw on/off) : off
RPA                   (rpa on/off) : off

INPUT MENU FOR GW CALCULATIONS WITH escf:
gw      : TURN STANDARD GW USING SPECTRAL FUNCTIONS (N^6) ON/OFF
rigw    : TURN RI-GW USING ANALYTIC CONTINUATION (N^4) ON/OFF
rpa     : TURN RPA MODULE (N^6) ON/OFF
Just <ENTER>, q or '*' terminate this menu.

This menu sets the flags for NMR shielding and coupling constant calculations as well as EPR properties. The nmr menu allows to switch between two different CPHF solvers for mpshiftand to set the corresponding keywords for both, for details see chapter 17.

ENTER SCF-OPTION TO BE MODIFIED
Old CPHF solver is selected (default up to V7.4)
Convergence is checked for the heaviest atom by default

STATUS OF NMR OPTIONS
 The old CPHF solver (up to V7.4) is used
 A threshold of 0.1000D-01 ppm is used
 Maximum number of iterations is set to    30
 NMR shieldings are calculated for all atoms

ENTER OPTION TO BE MODIFIED
 oldcphf    :  to switch on or off old CPHF solver (up to V7.4)
 csconv     :  to select convergence criterion for old solver
 rpaconv    :  to select convergence criterion for default solver
 csmaxiter  :  to select maximum number of iterations
 nucsel     :  to calculate certain nuclei only
 gimic      :  prepare input for GIMIC calculation
Just <ENTER>, q or * to terminate this menu.

The ncoup menu is used to control the input for a NMR coupling constant calculation with escf.

    STATUS OF OPTIONS FOR COUPLING CONSTANTS
The following terms will be calculated: fc sd pso dso fcsdcross
The threshold for the final output is      0.1000
Wave function convergence criteria is set to     9
Response convergence criteria is set to     6
Maximum number of iterations is set to    25
Response equations will be solved for all atoms
Right-hand side integrals will be calculated for all atoms

ENTER OPTION TO BE MODIFIED
 fc/sd/pso/dso on/only/off: set terms to be calculated
 fcsdcross/all on/off
 fromfile/simple
 thr      : threshold for final output
 scfconv  : convergence criterion for wave function (recommended: >= 7)
 rpaconv  : convergence criterion for response equations (recommended: >= 6)
 limit    : maximum number of iterations in response equations ($escfiterlimit)
 nucsel   : nuclei to solve response equations for
 nucsel2  : nuclei to calculate right-hand side integrals for
Just <ENTER>, q or * to terminate this menu

The settings are discussed in detail in chapter 8.

The EPR menu is used to control the input for an EPR with mpshift.

STATUS OF EPR OPTIONS
 We will perform an EPR calculation
 SNSO will be included for spin-orbit coupling
 SNSO parameter     3
 HFC and EFG are calculated for all atoms
 CPHF/CPKS convergence criterion     7
 Maximum number of iterations is set to    30

 ENTER OPTION TO BE MODIFIED
   epr        :  to turn on/off the EPR calculation
   snso       :  set options for spin-orbit treatment
   nucsel     :  to calculate certain nuclei only
   rpaconv    :  to select convergence criterion for CPHF/CPKS
   csmaxiter  :  to select maximum number of iterations
   current    :  current density and magnetic XC kernel for MGGAs/LHFs
Just <ENTER>, q or * to terminate this menu

Please see chapter 18 for details.

MP2, MP2-F12, RI-MP2, and PNO-MP2

We recommend to use MP2 for standard applications together with the RI technique using the ricc2 program. The mpgrad program is supplied for special benchmark application where the RI approximation needs to be avoided. The pnoccsd program is meant only for very large ($> 100$ atoms and $> 3000$ basis functions) MP2 and MP2-F12 single point energy calculations. This is more efficient and supports the frozen core option in the gradient calculation.

The entry mp2 leads to a submenu which allows to set some keywords for MP2 and RI-MP2 calculations, e.g. defining frozen orbitals, maximum memory usage, or assign auxiliary basis sets for RI-MP2 calculations, etc. If you want to use ricc2, you have to use the entry cc and the submenu ricc2 in order to assign MP2 as wavefunction model. For the pnoccsd program you have to use the entry pnocc and the submenu pnoccsd to assign the wavefunction model.

Conventional MP2 calculations with mpgrad require a number of additional settings for which it is recommended to invoke the interactive tool mp2prep. For geometry optimizations with jobex use nohup jobex -level mp2 -ri ...

CC2 and CCSD calculations

The entry cc leads to a submenu which allows to set a number of keywords essential for calculations with the programs ricc2 and ccsdf12. In particular it allows the assignment of the wavefunction method(s), selection of auxiliary basis sets, the specification of frozen orbitals, and the definition of a scratch directory and of the maximum core memory usage.

The ricc2 program must be used for excitation energies and response properties with second-order methods (MP2, CIS(D), ADC(2), CC2, etc. and their spin-scaled variants), while the ccsdf12 program must be used for third- and higher-order methods (MP3, CCSD, CCSD(T), etc.).

2nd analytical derivatives for SCF and DFT

The program aoforce computes force constants and IR and Raman Spectra on SCF and DFT level. Analytical second derivative calculations can directly be started from converged SCF or DFT calculations. Note, that the basis is restricted to $d$-functions, and ROHF as well as broken occupation numbers are not allowed. For better efficiency, in case of larger systems, use the keyword $maxcor as described in Chapter 15 to reduce computational cost. RI will be used if the RI option for DFT has been specified.

4.4.2 Special adjustments

Adjustments described by the following menus are often better done directly in the control file; have a look at the keywords in Chapter 25. For common calculations just start with the defaults, and change keywords directly in control if you encounter problems with your calculation.

SCF options

ENTER SCF-OPTION TO BE MODIFIED

conv   : ACCURACY OF SCF-ENERGY           $scfconv
thi    : INTEGRAL STORAGE CRITERIA        $thize  $thime
ints   : INTEGRAL STORAGE ALLOCATION      $scfintunit
iter   : MAXIMUM NUMBER OF ITERATIONS     $scfiterlimit
diis   : DIIS CONVERGENCE ACCELERATION    $scfdiis
damp   : OPTIONS FOR DAMPING              $scfdamp
shift  : SHIFTING OF ORBITALS             $scforbitalshift
order  : ORDERING OF ORBITALS             $scforbitalorder
fermi  : THERMAL SMEARING OF OCC. NUMBERS $fermi
pdiag  : PREDIAGONALIZATION               $prediag
soghf  : SPIN ORBIT GENERALIZED SCF       $soghf
x2c    : EXACT 2C HAMILTONIAN             $rx2c
rlocal : DLU SCHEME FOR X2C               $rlocal
finnuc : FINITE NUCLEUS MODEL             $finnuc
rsym   : RELATIVISTIC SYMMETRY            $rsym
snso   : SCREENED NUCLEAR SPIN ORBIT      $snso

By the command $fermi you can switch on smearing of occupation numbers, and thus automatically optimize occupations and spin [55]. The command $soghf guides the user for the different settings of a two-component calculation. Relativistic effects are included by ECPs or relativistic all-electron methods, see section 6.5.

The most important of the derivative menus is the first one which tells the programs which derivatives to calculate. This is only necessary for special purposes and you should better not change default options.

------------------------------------------------------------------------
 derivative data groups '$drvopt, $drvtol'
------------------------------------------------------------------------
 option | status  | description :
------------------------------------------------------------------------
 crt    |    T    | CARTESIAN 1st derivatives
 sec    |    T    | CARTESIAN 2nd derivatives
 bas    |    F    | energy derivatives with respect to
        |         |  BASIS SET exponents/scaling factors/
        |         |  contraction coefficients
 glb    |    F    | energy derivative with respect to
        |         |  a GLOBAL scaling factor
 dip    |    T    | cartesian 1st derivatives of DIPOLE MOMENT
 pol    |    T    | nuclear contribution to POLARIZABILITY
 fa     |    F    | SPECTROSCOPIC ANALYSIS only
 tol     0.100D-06  derivative integral cutoff
------------------------------------------------------------------------
 use <opt> for enabling, -<opt> for disabling of logical switches
 <&> will bring you back to GENERAL MENU without more changes
 <RETURN> OR * OR q(uit) WILL TERMINATE THIS MENU

The handling of these options is very simple. With the exception of tol, all are logical switches which are either true (or on, active) or false (or off, inactive). You can switch between the two states if you enter, for example, crt (to switch calculation of Cartesian first derivatives on) or -crt (to switch it off). The options crt, sec and bas should provide no problems. glb refers to a global scaling factor for all basis set exponents. Imagine that you would like to replace your basis set, which contains basis functions \[\begin{equation*} \chi_\mu=(x-x_0)^l(y-y_0)^m(z-z_0)^n\exp\left[-\eta_\mu(r-r_0)^2\right] \end{equation*}\] by another basis set which contains basis functions \[\begin{equation*} \chi_\mu=(x-x_0)^l(y-y_0)^m(z-z_0)^n\exp\left[-\alpha\eta_\mu(r-r_0)^2\right] \end{equation*}\] where $\alpha$ is the same for all primitive basis functions $\chi_\mu$. With command glb you are able to calculate analytical derivatives of the total energy with respect to $\alpha$ and can thus easily determine the optimum $\alpha$.

dip enables you to calculate the first derivatives of the electric dipole moment with respect to nuclear displacements which gives you infrared intensities. pol allows you to calculate the contribution of the nuclear rearrangement on the electric polarizability. fa finally performs only a frequency analysis which means that aoforce will read the force constant matrix ($hessian or $hessian (projected)), diagonalize it and give you the frequencies and normal modes. tol is not a logical switch as the other options in this menu, but a cutoff threshold for the derivative integrals, i.e. integrals below this threshold will be neglected in the derivative calculations.

Entering * will bring you to the second derivative submenu.

Debug Options for the Derivative Programs

The following menu deals only with some debug options for grad. Use them with caution, each of them can produce lots of useless output:

------------------------------------------------------------------------
 derivative debug options '$drvdebug'
------------------------------------------------------------------------
 option  |status| description :
------------------------------------------------------------------------
 disp1e  |   F   | display 1e contributions to desired derivatives
 only1e  |   F   | calculate 1e contributions to desired derivatives only
 debug1e |   F   | display 1e shell contributions to desired derivatives
         |       |  (WARNING : this produces large outputs!)
 debug2e |   F   | display 2e shell contributions to desired derivatives
         |       |  (WARNING : this produces VERY large  outputs!)
 debugvib|   F   | debug switch for vibrational analysis (force only)
 notrans |   F   | disable transfer relations (gradient only!)
 novirial|   F   | disable virial scaling invariance in basis set
         |       |  optimizations (gradient only)
------------------------------------------------------------------------
 use <opt> for enabling, -<opt> for disabling option <opt>
 <&> will bring you back to GENERAL MENU without more changes
 <RETURN> OR * OR q(uit) WILL TERMINATE THIS MENU

As there is no need to use these options normally and the menu text is self-explaining, no further description will be given. Note that all options are logical switches and may be enabled and disabled the same way as shown for the last menu. Entering * will bring you to the last derivative submenu.

4.4.3 Relax Options

Program relax has a huge variety of options to control its actions which in program define are grouped together in eight consecutive menus. These are only briefly described in the following sections; for a more detailed discussion of the underlying algorithms refer to the documentation of program relax (see Section 5.3). Only experts should try to change default settings.

Optimization Methods

The first of the relax subgenus deals with the type of optimization to be performed:

------------------------------------------------------------------------
 optimization options for RELAX
------------------------------------------------------------------------
 option | status | description : optimization refers to
------------------------------------------------------------------------
 int    |    F   | INTERNAL coordinates
 crt    |    F   | CARTESIAN coordinates
 bas    |    F   | BASIS SET exponents/scale factors
 glb    |    F   | GLOBAL scaling factor
------------------------------------------------------------------------
 use <opt> for enabling, -<opt> for disabling option <opt>
 <RETURN> OR * OR q(uit) WILL TERMINATE THIS MENU

You can choose between a geometry optimization in the space of internal coordinates (in this case you will need definitions of internal coordinates, of course) or in the space of Cartesian coordinates (these possibilities are mutually exclusive, of course). Furthermore optimizations of basis set parameters (exponents, contraction coefficients and scaling factors) or of a global scaling factor is possible (these options are also exclusive, but can be performed simultaneous to a geometry optimization). For the geometry optimization you should normally use internal coordinates as they provide better convergence characteristics in most cases.

Coordinate Updates

The next submenu deals with the way relax updates the old coordinates. You may choose a maximum change for the coordinates or you can allow coordinate updates by means of extrapolation:

------------------------------------------------------------------------
 coordinate update options for RELAX
------------------------------------------------------------------------
 dqmax <real> : coordinates are allowed to change by at most
                <real> (DEFAULT : 0.3000    ) a.u.
 polish       : perform an interpolation or extrapolation of
                coordinates (DEFAULT :y)
 -polish      : disable inter/extrapolation
------------------------------------------------------------------------
 <RETURN> OR * OR q(uit) WILL TERMINATE THIS MENU

These options result in better convergence of your optimization in most cases.

Interconversion Between Internal and Cartesian Coordinates

The interconversion between internal and Cartesian coordinates is not possible directly (in this direction). Instead it is performed iteratively. The following options control this conversion:

--------------------------------------------------------------------
interconversion options for RELAX
--------------------------------------------------------------------
option    | description
--------------------------------------------------------------------
on        | switch on interconversion (DEFAULT: off)
qconv <r> | set convergence threshold for interconversion
          | of coordinates to <r>. DEFAULT : <r> =  .1000E-09
iter <i>  | allow at most <i> iterations for interconversion
          | of coordinates. DEFAULT : <i> =   25
crtint    | transform cartesian into internal coordinates (DEFAULT=n)
intcrt    | transform internal into cartesian coordinates (DEFAULT=n)
grdint    | transform cartesian into internal gradients (DEFAULT=n)
hssint    | transform cartesian into internal hessian (DEFAULT=n)
--------------------------------------------------------------------
use -<opt> for disabling any interconversion option
<RETURN> OR * OR q(uit) WILL TERMINATE THIS MENU

The options qconv and iter are used in each normal relax run to determine the characteristics of the back-transformation of coordinates into the internal space. With the other options and interconversion switched on, you can force relax to perform only the specified coordinate transformation and write the transformed coordinates to file control. To achieve this, enter on to switch to the transformation-only mode, and one of the last four options, e.g. crtint, to specify the desired transformation.

Updating the Hessian

relax provides a variety of methods to generate an updated Hessian every cycle. This includes the well known methods such as BFGS, DFP, or MS update methods as well as some less common procedures:

--------------------------------------------------------------
OPTIONS FOR UPDATING THE HESSIAN
--------------------------------------------------------------
 option  | status | description
--------------------------------------------------------------
none     |    F   | NO UPDATE (STEEPEST DESCENT)
bfgs     |    F   | BROYDEN-FLETCHER-GOLDFARB-SHANNO UPDATE
dfp      |    F   | DAVIDON-FLETCHER-POWELL UPDATE
bfgs-dfp |    F   | COMBINED (BFGS+DFP) UPDATE
ms       |    F   | MURTAGH-SARGENT UPDATE
schlegel |    F   | SCHLEGEL UPDATE
diagup   |    F   | DIAGONAL UPDATE (AHLRICHS/EHRIG)
multidim |    F   | RANK > 2 BFGS-TYPE UPDATE
ahlrichs |    T   | MACRO : AHLRICHS UPDATE (DEFAULT)
--------------------------------------------------------------
USE <opt> FOR ENABLING OPTION <opt> AND THUS DISABLING
ALL OTHER OPTIONS.
<RETURN> OR * OR q(uit) WILL TERMINATE THIS MENU

We recommend to use the default method ahlrichs which provides excellent convergency in most cases.

General Boundary Conditions for Update

The force constant matrix will only be updated if least mingeo cycles exist. The maximum number of cycles used for the update is specified by the parameter maxgeo. Normally the default values provided by define need not be changed.

DEFINE BOUNDARY CONDITIONS FOR UPDATE
--------------------------------------------------------------
mingeo <i> | START UPDATE IF THERE ARE AT LEAST <i> CYCLES
           | DEFAULT : min   3
maxgeo <i> | USE LAST <i> CYCLES FOR UPDATE, DEFAULT : max   4
--------------------------------------------------------------
<RETURN> OR * OR q(uit) WILL TERMINATE THIS MENU

Special Boundary Conditions for Ahlrichs and Pulay Updates

For the default update method ahlrichs some additional control parameters are available which can be defined in this menu:

DEFINE BOUNDARY CONDITIONS FOR AHLRICHS OR PULAY UPDATE
--------------------------------------------------------------
option    | description
--------------------------------------------------------------
modus <i> | DEFINE MODUS FOR GDIIS PROCEDURE : MINIMIZE
          |  <dq|dq> IF  <i> = 0
          |  <g|dq>  IF  <i> = 1
          |  <g|g>   IF  <i> = 2
          |  <dE>    IF  <i> = 3
          | DEFAULT : <i> = 1
fail <r>  | IGNORE GDIIS IF  <g|dq> /| <g|dq> | IS
          | LARGER THAN -<r>. DEFAULT : <r> = 0.1
--------------------------------------------------------------
<RETURN> OR * OR q(uit) WILL TERMINATE THIS MENU

For detailed description consult Section 5.3.

--------------------------------------------------------------
OPTIONS FOR MANIPULATING THE HESSIAN
--------------------------------------------------------------
 option      | description
--------------------------------------------------------------
diagonal     | RESTRICT UPDATE TO DIAGONAL-ELEMENTS IF
             | METHOD IS BFGS,DFP OR MS. DEFAULT=n
offreset     | DISCARD OFF-DIAGONAL ELEMENTS. DEFAULT=n
offdamp <r>  | DAMP OFF-DIAGONAL ELEMENTS BY 1/(1+<r>) DEFAULT= 1.000
damp <real>  | DAMP UPDATE BY 1/(1+<real>), DEFAULT= .0000E+00
scale <real> | SCALE INPUT HESSIAN BY <real>, DEFAULT= 1.000
allow <real> | SCALE INPUT HESSIAN BY <real>/|DE| IF |DE|,
             | THE OBSERVED ABSOLUTE CHANGE IN ENERGY, IS
             | OBEYING THE CONDITION |DE| > <real> > 0.
             | DEFAULT : NO SCALING
min <real>   | DO NOT ALLOW EIGENVALUES OF HESSIAN TO DROP
             | BELOW <real>. DEFAULT= .1000E-02
reset <real> | USE <real> AS A RESET VALUE FOR TOO SMALL
             | EIGENVALUES (CP. min). DEFAULT= .1000E-02
max <real>   | DO NOT ALLOW EIGENVALUES OF HESSIAN TO BECOME
             | LARGER THAN <real>. DEFAULT= 1000.
--------------------------------------------------------------
WITH THE EXCEPTION OF min,reset AND max, ALL OPTIONS MAY BE
DISABLED BY ENTERING -<opt>
<RETURN> OR * OR q(uit) WILL TERMINATE THIS MENU

Initialization of the Hessian

Finally there are some options to control the choice of the initial Hessian during your geometry optimization:

--------------------------------------------------------------
FORCE CONSTANTS INITIALIZATION OPTIONS FOR RELAX
--------------------------------------------------------------
OPTION    | DESCRIPTION
--------------------------------------------------------------
off       | switch off initialization (DEFAULT: on)
cart      | use analytical cartesian hessian provided by a
          | 2nd derivatives calculation. DEFAULT(n)
diag      | use diagonal matrix with diagonal elements set
          | individually within data groups $intdef or
          | $basis or $global. DEFAULT(n)
unit <r>  | use multiple of the unit matrix ( H = <r>*E ).
          | DEFAULT(n) - DEFAULT <r> =  1.000
--------------------------------------------------------------
NOTE THAT THESE OPTIONS ARE MUTUALLY EXCLUSIVE
<RETURN> OR * OR q(uit) WILL TERMINATE THIS MENU

Option off will be used if you have already a good Hessian from a previous calculation which may be used. cart describes an even better state where you have a Hessian from a calculation of the second derivatives available (aoforce). The other two options describe real procedures for initialization of the Hessian. Default values: stretches (0.5), angles (0.2).

4.4.4 Definition of External Electrostatic Fields

This submenu allows you to calculate first and second numerical derivatives of the energy with respect to an external electric field. The first three options should be clear; 1st and 2nd are logical switches which are turned on and off the usual way (1st or -1st) and delta is the increment for the numerical differentiation, that is, the finite value of the external field, which replaces the (ideally) differential field:

--------------------------------------------------------------------
electrostatic field definition menu
--------------------------------------------------------------------
option       | status | description
--------------------------------------------------------------------
1st          |    F   | numerical 1st derivative dE/dField
2nd          |    F   | numerical 2nd derivative d2E/dField2
delta <real> |        | increment for numerical differentiation
             |        | DEFAULT =    .5000E-02
geofield     |    F   | geometry optimization with external field
man          |    F   | explicit definition of electrostatic field(s)
--------------------------------------------------------------------

geofield gives the possibility to perform a whole geometry optimization under the influence of a finite external field and thus to obtain the (distorted) minimum geometry in this field. To do this, an external electrostatic field must be defined explicitly which can be done using command man. Note that geofield must also be switched on if any properties are to be evaluated in the presence of an electric field. The most prominent example is the calculation of hyperpolarizabilies.

Take Care, due to some inconsistencies in define it is always necessary to switch on the field calculations manually. Therefore edit the control file after having finished your define session and enter on after the entries of fields and geofield.

4.4.5 Properties

Most properties can be calculated with the -proper option in the corresponding modules like dscf or ridft directly. Previously, the program moloch was used for this purpose and define is still able to use the old menu for moloch (see below). For a detailed list of the keywords, please see Sec. 25.2.29. If you enter prop in the general menu, define first will check whether the data group $properties does already exist in your control file or in a file referenced therein. If this is not the case you will be asked to specify the file on which $properties shall be written:

 CURRENT STATUS OF PROPERTY KEYWORDS:

 NO KEYWORDS FOR CALCULATION OF PROPERTIES ARE SET


 SELECT ONE OF THE FOLLOWING OPTIONS:

  mvd   : Calculation of p^4 and Darwin term
  pop   : population analyses (-> submenu)
  loc   : calculation of localized orbitals
  esp   : ESP-fit
  plt   : Calculation of densities, MOs, etc. on a grid; e.g.
          for further use in visualization programs (keqword: $pointval) 
  old   : old menu for moloch
  *     : leave this submenu

All keywords can be disabled by using the same option again and then selecting to deactivate the input (*).

Option `mvd`

The option mvd directly activates the calculation of the relativistic mass-velocity and the Darwin term based on perturbation theory.

Option `esp`

The option esp directly activates the calculation of the electrostatic potential (ESP) fit.

Option `pop`

Activating pop drives the calculation of various population analyses.

 YOU MAY CHOOSE BETWEEN:

  mul:   Mulliken PA
  low:   Loewdin  PA
  nbo:   natural  PA
  pab:   PA basen on occupation numbers
  wbi:   Wiberg bond indices
  all:   all of the above PAs
  *  :   continue without activating any PA

After selecting one of the analyses, all atoms and bonds or a subset can be considered. It is recommended to run the PA for the full molecule as the evaluation is not time-determing. Note that Wiberg bond indices are always calculated for all bonds.

Option `loc`

Activating loc allows to setup the input for constructing localized molecular orbitals according to the Foster–Boys scheme.

 CHOOSE ORBITALS FOR LOCALIZATION (default=all)

  m <list> : MOs from list are included
  ge <thr> : above list is generated automatically.
             It will contain MOs with energies 
             e(HOMO)-thr < e <= e(HOMO)
  gn <int> : above list is generated automatically.
             It will contain the <int> highest
             occupied MOs
  lm <no> : list highest <no> occupied MOs
                (default: no=200)
  *       : activate localization and continue

  NOTE: for further options see manual

For other localization schemes such as the Pipek-Mezey method or intrinsic bond orbitals (IBOs) and the required keywords, please see Sec. 25.2.29.

Option `plt`

Using the option plt inserts the necessary keywords to calculate various quantities such as MOs, LMOs or the electron localization function on a grid. The default format is plt, which can be opened by TmoleX or gOpenMol. Other formats can be selected in define. A post-processing script to convert plt to other frequently used formats in quantum chemistry is available at the homepage of the TURBOMOLE project, please see https://www.turbomole.org/turbomole/utilities/.

 YOU MAY CHOOSE BETWEEN:

  m <list> : plot for MOs from <list>
  ge <thr> : above list is generated automatically.
             It will contain MOs with energies 
             e(HOMO)-thr < e <= e(HOMO)
  gn <int> : above list is generated automatically.
             It will contain the <int> highest
             occupied MOs
  lm <no>,<nv> : list highest <no> occupied and lowest <nv> 
                virtual MOs (default: no=20, nv=1)
  e        : plot electron localization function (ELF)
  f <fmt>  : change format; default is plt; further options:
                          map, xyz, plv (see also manual)
  d        : plot densities (default)
  *        : activate $pointval and continue

  NOTE: for further options see manual

Option `old`

The program moloch was previously used for the calculation of properties and analysis of the wave function. The subsequent description for an older version may not work in all cases—sorry for that.

If you enter prop in the general menu and use the option old, define first will check whether the data group $properties does already exist in your control file or in a file referenced therein. If this is not the case you will be asked to specify the file on which $properties shall be written:

data group $properties has not yet been specified
FOR INITIALIZING <moloch> KEYWORDS ENTER
  [return] : WRITE TO CONTROL FILE control (DEFAULT),   OR
  filename : WRITE TO ANOTHER FILE

Afterwards you will get the following submenu which allows you to control all possible actions of program moloch:

switch on one or more of the following options <i>
<i> = 1,..., 9
for switching off option <i>, specify -<i>
( 1) trace                                     off
( 2) moments                                   off
( 3) potential                                 off
( 4) cowan-griffin                             off
( 5) localization                              off
( 6) population analyses                       off
( 7) plot                                      off
( 8) firstorder                                off
selecting an already active option indicates that
suboptions shall be modified
* or q(uit) = quit | for help, type help <integer>

All options in this menu are selected by entering their number as indicated in the first column. For example, to switch on option trace enter 1. The flag off will then change to active. To switch off an option enter its negative number, e.g. -1 for trace. Most of the options require additional input and will therefore lead you to further submenus. These are briefly described below.

Option trace

trace will calculate the trace of density times overlap matrix: \[\begin{equation*} N = \mbox{tr}\{\mathbf{DS}\} \end{equation*}\] If the orbitals are orthonormal, $N$ should yield the total number of electrons in your molecule. If this is not true, your MO-vector will most probably be erroneous. For example, the vector might belong to another geometry or basis set. As this is a very sensitive test for errors like these and the calculation requires almost no time, you should always switch on this option.

Option moments

This option leads you to the following submenu:

add/change options for data group $moments
option            | status | description
------------------|--------|-------------------------------
point <x> <y> <z> |    T   | reference point = (x,y,z)
atom <i>          |    F   | reference point = atom no. <i>
0th               |    T   | compute 0th moment
1st               |    F   | compute 1st moment
2nd               |    F   | compute 2nd moment
3rd               |    F   | compute 3rd moment
------------------|--------|-------------------------------
-<moment>   : skip computation of <moment>
* or q(uit) : terminate input

This menu serves to specify the electrostatic moments to be calculated (0th=charge, 1st=dipole moment, 2nd=quadrupole moment, 3rd=octuple moment). The reference point is the origin of the coordinate system used in the calculation. The value of any calculated moment will be independent of this reference point, if all lower moments are zero. The default for the reference point is the origin, i.e. the coordinate system used for the calculation of the moments will be the same as the one in which the atomic coordinates are specified. The reference point may be changed by typing point with the three new coordinates appended. Alternatively you may choose the coordinates of one of the atoms as reference point by entering atom and the atom index.

Option potential

This option collects all possible quantities related to the electrostatic field created by the molecular charge distribution. This includes the following suboptions:

list of suboptions :
pot          - electrostatic potential
fld          - electrostatic field
fldgrd       - electrostatic field gradient
shld         - diamagnetic shielding
file         - file reference
*            - quit

The meaning of the four suboptions pot, fld, fldgrd and shld will probably present no problems to you. For each of them, however, you will have to specify at which point(s) this property should be calculated. This is accomplished by one or more data groups $points in file control. After you chose one or more of the above options, you will therefore reach the next submenu which deals with the specification of these data groups:

there are     1 data groups $points
manipulate data group(s) $points
a             - add another data group
m <integer>   - modify <integer>th data group
m all         - modify all data groups
d <integer>   - delete <integer>th data group
d all         - delete all data groups
off <integer> - switch off <integer>th data group
off all       - switch off all data groups
on <integer>  - switch on <integer>th data group
on all        - switch on all data groups
s             - scan through data groups
*             - quit

The first line informs you how many of these data groups already exist in your control file. Each of these data groups may consist of several points at which the properties will be calculated. You may now create new data groups, delete old ones or simply switch on or off individual data groups (without deleting them from control). The number of different data groups $points as well as the number of points in each of them are not limited. However, if you use many points, you should consider specifying them in a separate file. This is most easily done using option file in the potential menu. This option will create a file for your data groups $points and will write a reference of this file to file control.

Option cowan-griffin

This option activates the computation of the first order relativistic correction to the energy as given by the expectation value of the Cowan–Griffin operator.

Option localization

Specifying option localization will switch on a Boys localization of molecular orbitals. define by default chooses a set of MOs to be localized according to a certain threshold for the orbital energy. Information about these are displayed like this:

BOYS localization will be performed with respect to x y z
number of sweeps =      10000
subset of molecular orbitals to be localized :
---> all occupied molecular orbitals
     with orbital energy above -2.00000     Hartree
----------------------------------------------------------------
 shells to be localized
----------------------------------------------------------------
a1       4-5                                         #   1-   5
e        2                                           #   1-   2
----------------------------------------------------------------
you are employing default options for localization
do you want to modify them ? DEFAULT(n)

If you want to change the MO selection or other options for the localization enter y at this point (By default or when typing n you will reach the moloch options menu again). You will then be asked whether to change the MO selection method. If you want this, you will enter a little submenu where you can choose one of three possible selection procedures:

all: selects all occupied orbitals
thr: selects all occupied orbitals with orbital energy larger than a certain threshold
man: enables you to select the MOs manually later in this section

If the selection method thr is specified you then will be asked for the threshold to be applied for the selection. Afterwards you have the possibility to change some other topics concerning the localization:

specify other localization directions
switch on utilization of localized orbitals for population analysis and/or preparation of plot data within the same moloch run
set the maximum number of sweeps in the localization procedure
specify a file where localized orbitals shall be written to

Option population analyses

When activating this option you first have to specify whether the population analysis (PA) should be performed in the CAO (default) or AO basis. Afterwards define will ask you whether you want to perform a Mulliken population analysis. In this case, the following submenu will be displayed:

add or delete one or more special options for a
mulliken population analysis
 option | status | description
 -------|--------|---------------------------------------
 spdf   |    F   | compute MO contributions to atomic
        |        | brutto populations
 molap  |    F   | compute MO contributions to atomic
        |        | overlap populations
 netto  |    F   | compute atomic netto populations
 irpspd |    F   | compute IRREP contributions to atomic
        |        | brutto populations
 irpmol |    F   | compute IRREP contributions to atomic
        |        | overlap populations
 mommul |    F   | print electrostatic moments resulting
        |        | from atomic charges
 -------|--------|---------------------------------------
 -<option>   : switch off <option>
 * or q(uit) : leave this menu

Here you can activate several optional quantities to be computed along with the Mulliken PA. To switch on one or more of these options you must enter the corresponding option keywords, e.g. spdf netto for computation of atomic net populations and MO contributions to atomic gross populations. The status flags for these tasks will then change from F (false) to T (true). To switch off any option you simply have to enter the corresponding keyword preceded by a ‘-’, e.g. -netto for disabling calculation of atomic net populations.

After having left the Mulliken PA section you will be asked whether a population analysis based on occupation numbers (a modified Roby–Davidson PA) should be performed by moloch. When typing y you will see the following submenu, where you can switch on several special options for the PA in the same manner as described above.

add or delete one or more special options for a
population analysis based on occupation numbers
 option  | status | description
 --------|--------|----------------------------------------
 momao   |    F   | compute MO contributions to modified
         |        | atomic orbital (MAO) occupation numbers
 maodump |    F   | dump all MAOs onto standard output
 maofile |    F   | write MAOs onto a separate file
 select  |    F   | write only those MAOs which have been
         |        | employed in the population analysis
 all     |    F   | write all MAOs
 --------|--------|----------------------------------------
 note that the options select and all are complementary
 -<option>   : switch off <option>
 * or q(uit) : leave this menu

Afterwards you have the possibility to change the criterion to be applied for the selection of modified atomic orbitals (MAOs) within the following little submenu:

global criterion for selection of Modified Atomic Orbitals (MAOs) :
-------------------------------------------------------------------
 MAOs are employed if 'atomic' density eigenvalues
 exceed a threshold of  .1000
-------------------------------------------------------------------
 specify the appropriate option if you want to use another
 global criterion for selecting MAOs
 option  | status | description
 --------|--------|---------------------------------------
 eig <r> |    T   | select by eigenvalues of the
         |        | 'atomic' density matrices
 occ <r> |    F   | select by occupation numbers
 --------|--------|---------------------------------------
 <r> is the selection threshold (DEFAULT= .1000    )
 * or q(uit) : leave this menu

The criterion applied by default is the so-called atomic density eigenvalue with a threshold of $0.1$. You can switch the criterion to occupation numbers by entering occ. If you also want to change the threshold, you just have to append its new value to the selection keyword, e.g. occ .2. Finally you can select or disable various options in connection with the computation of shared electron numbers (SEN) within the following menu:

actual settings for data group $shared electron numbers
 2-center shared electron numbers will be computed;
 values are printed if absolute value exceeds    .0100
 3-center shared electron numbers will be computed;
 values are printed if absolute value exceeds    .0100
 4-center shared electron numbers will be computed;
 values are printed if absolute value exceeds    .0100
add or delete one or more options for the
computation of Shared Electron Numbers (SEN)
 option  | status | description
 --------|--------|----------------------------------------
 2c <r>  |    T   | compute 2-center SEN and print if
         |        | |SEN| > <r> (DEFAULT =  .1000E-01)
 3c <r>  |    T   | compute 3-center SEN and print if
         |        | |SEN| > <r> (DEFAULT =  .1000E-01)
 4c <r>  |    T   | compute 4-center SEN and print if
         |        | |SEN| > <r> (DEFAULT =  .1000E-01)
 --------|--------|----------------------------------------
 nosym   |    F   | switch off use of symmetry
 orbs    |    F   | compute orbital contributions to SEN
 irreps  |    F   | compute irrep contributions to SEN
 --------|--------|----------------------------------------
 -<option>   : switch off <option>
 * or q(uit) : leave this menu

The procedure for changing the options is the same as described above. By default calculation of 2-, 3- and 4-center SENs will be enabled with thresholds of $0.01$ each.

Option plot

This option allows you to prepare the data needed for contour plots of orbital amplitudes or total electron densities. We do not recommend to prepare plotting data this way; an easier method—with an easier syntax—is to generate these data directly by the programs, where densities (also MP2 or excited ones) and Molecular orbitals are calculated. This is described in Chapter 22. If you nevertheless want to prepare the input for plotting data as needed by moloch using define, on activating plot you get the following menu:

there are     1 data groups $grid
manipulate data group(s) $grid
 a             - add another data group
 m <integer>   - modify <integer>th data group
 m all         - modify all data groups
 d <integer>   - delete <integer>th data group
 d all         - delete all data groups
 off <integer> - switch off <integer>th data group
 off all       - switch off all data groups
 on <integer>  - switch on <integer>th data group
 on all        - switch on all data groups
 s             - scan through data groups
 *             - quit

The commands in this menu serve for the manipulation of data groups $grid in an analogous way as described for $points in the potential section above. $grid data groups contain the input information necessary to create the plot data by moloch (one data group for each plot). If you want to add a new data group you will enter this submenu:

specify the input orbital / input density :
mo <label>    - use occupied molecular orbital <label>
mo density    - use one electron density built from the
                occupied molecular orbitals
lmo <i>       - use localized molecular orbital no. <lmo>
mao <i> <k>   - use modified atomic orbital no. <i>
                centered on atom no. <k>
help          - explanation of the syntax for <label>
*             - quit

Here you may specify the orbital to be plotted. To plot the amplitude of the fifth orbital in irrep a1, e.g., you would enter mo 5a1. Equivalently you can use localized orbitals from a Boys localization procedure or modified atomic orbitals as obtained in a Roby–Davidson–Ahlrichs–Heinzmann population analysis. In the latter cases you will not have to enter an irrep label, as these orbitals are necessarily in $C_1$ symmetry. Instead you will have to enter the index of the orbital to be plotted (and for option mao the index of the atom at which it is situated). In all cases you will additionally have to specify the plane in which the amplitudes or densities will be monitored. To do this, you have to declare two vectors which span that plane and the origin of this new coordinate system relative to the one in which the atomic coordinates are given. Furthermore, you will have to create a grid of points on this plane. The orbital amplitude or electron density will then be calculated for every point in this grid. The grid is created by telling define the range to be included along both vectors spanning the plane (where the unit in each direction is the length of the corresponding basis vector) and the number of points to be calculated in this range. It is advantageous to use a wide grid while you test the ranges or planes which give the best results and then to switch to a finer grid for the final calculation. Finally input (MO vector) and output (plot data) files can be specified.

In case you do not want to add a new data group as described above but to change an existing one, you will be asked which one of the specifications you want to modify.

4.4 The General Options Menu

4.4.1 Important commands

DFT calculations

RI-J calculations

MARI-J option

Multiple auxiliary basis sets

RI in SCF calculations

Optimization to minima and transition structures using Statpt

Excited states, frequency-dependent properties, and stability analysis

Menu nmr, ncoup, and epr

MP2, MP2-F12, RI-MP2, and PNO-MP2

CC2 and CCSD calculations

2nd analytical derivatives for SCF and DFT

4.4.2 Special adjustments

SCF options

Menu drv

Debug Options for the Derivative Programs

4.4.3 Relax Options

Optimization Methods

Coordinate Updates

Interconversion Between Internal and Cartesian Coordinates

Updating the Hessian

General Boundary Conditions for Update

Special Boundary Conditions for Ahlrichs and Pulay Updates

Initialization of the Hessian

4.4.4 Definition of External Electrostatic Fields

4.4.5 Properties

Option `mvd`

Option `esp`

Option `pop`

Option `loc`

Option `plt`

Option `old`

4.4 The General Options Menu

4.4.1 Important commands

DFT calculations

RI-J calculations

MARI-J option

Multiple auxiliary basis sets

RI in SCF calculations

Optimization to minima and transition structures using Statpt

Excited states, frequency-dependent properties, and stability analysis

Menu nmr, ncoup, and epr

MP2, MP2-F12, RI-MP2, and PNO-MP2

CC2 and CCSD calculations

2nd analytical derivatives for SCF and DFT

4.4.2 Special adjustments

SCF options

Menu drv

Debug Options for the Derivative Programs

4.4.3 Relax Options

Optimization Methods

Coordinate Updates

Interconversion Between Internal and Cartesian Coordinates

Updating the Hessian

General Boundary Conditions for Update

Special Boundary Conditions for Ahlrichs and Pulay Updates

Initialization of the Hessian

4.4.4 Definition of External Electrostatic Fields

4.4.5 Properties

Option mvd

Option esp

Option pop

Option loc

Option plt

Option old

Option `mvd`

Option `esp`

Option `pop`

Option `loc`

Option `plt`

Option `old`