25.2.5 Other General Keywords

$operating system unix
$path
$lock off
$suspend off

The four keywords above are set by define, but are not necessary.

$statistics dscf
or
$statistics mpgrad

Only a statistics run will be performed to determine file space requirements as specified for dscf or mpgrad. On return the statistics option will be changed to $statistics off.

$actual step dscf

means current step. Keyword and data group (as e.g. dscf) is set by every program and removed on successful completion.

$last step relax

Keyword and data group (as e.g. relax) set by every program on successful completion.

General file cross-references:

$coord              file=coord
$intdef             file=coord
$user-defined bonds file=coord
$basis         file=basis
$ecp           file=basis
$jbas          file=auxbasis
$scfmo           file=mos
$uhfmo_alpha     file=alpha
$uhfmo_beta      file=beta
$natural orbitals           file=natural
$natural orbital occupation file=natural
$energy        file=energy
$grad          file=gradient
$forceapprox   file=forceapprox

It is convenient not to include all input in the control file directly and to refer instead to other files providing the corresponding information. The above cross references are default settings from define; you may use other file names. define will create most of these files. Examples of these files are given below in the samples.

$coord (and $intdef and $userdefined bonds): contains atom specification—type and location—and the bonds and internal coordinates convenient for geometry optimizations.
$basis: specification of basis sets.
$ecp: specification of effective core potentials.
$jbas: auxiliary (fitting) basis for the Coulomb terms in ridft.
$scfmo, $uhfmo_alpha, $uhfmo_beta: MO vectors of SCF or DFT calculations for RHF or UHF runs.
$natural orbitals, $natural orbital occupation: keywords and data groups set by unrestricted dscf or ridft runs. Contain natural MO vector and orbital occupation.
$energy, $grad: energies and gradients of all runs, e.g. for documentation in a geometry optimizations.
$forceapprox: approximate force constant for geometry optimizations.