TURBOMOLE manual
v8.0

25.2.22 Keywords for Module mpgrad

If an MP2 run is to be performed after the SCF run, the SCF run has to be done with at least

1) density convergence $denconv 1.d-7
2) energy convergence $scfconv 6

$maxcor n

The data group $maxcor adjusts the maximum size of core memory (n in MB) which will be allocated during the MP2 run. Recommendation: 3/4 of the actual main memory at most. For further details see subsection 25.2.3.

$mp2energy

Calculation of MP2 gradient is omitted, only MP2 energy is calculated.

$freeze

Freeze orbitals in the calculation of the MP2 correlation energy. For details see Section 25.2.4.

All essential data groups for mpgrad may be generated by the preparation tool mp2prep, apart from $maxcor (see above) these are the following:

$traloop n

specifies the number of loops (or ’passes’) over occupied orbitals, n, performed in the mpgrad run: the more passes the smaller file space requirements—but CPU time will go up.

$mointunit
 type=intermed unit=61       size=0        file=halfint
 type=1111     unit=62       size=0        file=moint#0
 type=1112     unit=63       size=0        file=moint#1
 type=1122     unit=64       size=0        file=moint#j
 type=1212     unit=65       size=0        file=moint#k
 type=1212a    unit=70       size=0        file=moint#a
 type=gamma#1  unit=71       size=0        file=gamma#1
 type=gamma#2  unit=72       size=0        file=gamma#2
 type=1212u    unit=73       size=0        file=moint#u
 type=1112u    unit=74       size=0        file=moint#v
 type=gamma#1u unit=75       size=0        file=gamma#1u

The data group $mointunit specifies:

  • which scratch files are needed,

  • where they are located (path name) and

  • (after a statistics run, see below) an estimated file size.

$statistics mpgrad

statistics run (estimation of disc space needed) for the adjustment of the file sizes will be performed.

$mp2pair

calculation of MP2 pair correlation energies.