Calculations with mpgrad

1. Add $denconv 1.d-7 to the control file and perform a dscf run.
2. If any orbitals are decided to be excluded from MP2 treatment, add data group $freeze manually to the control file, see also Section 15.2.12.
3. For preparation of an mpgrad run use the script Mp2prep:
   mp2prep -e/g -m memory -p discspace [scratch file directory]
   As an example, with the command
   mp2prep -e -m 100 -p 1000 /work
   an MP2-energy calculation is prepared, the amount of available core memory is restricted to 100 MB, the MOs are blocked, so that integral scratch files--located in the directory /work--do not need more than 1000Mb. The number of blocks, i.e. the number of passes with repeated integral evaluations, is written to the control file ($traloop) as well as the specification of scratch files ($mointunit, see Section 15.2.12). Note: less disc space means more passes and thus lower efficiency of mpgrad, but due the technical limitations discspace should be limited to values < 16Gb to avoid integer overflow errors. Settings obtained by mp2prep may be changed manually. You may change the number of passes in $traloop by editing the control file (e.g. if the originally intended disc space is not available). To adapt the size of scratch files add $statistics mpgrad to control file and start an mpgrad statistics run with the command mpgrad.
4. Start a single mpgrad calculation with the command mpgrad.
5. For optimisation of structure parameters at the (non-RI-) MP2 level use the command jobex -level mp2. Note, that the frozen core approximation is ignored in this case.

General Comments