Keywords for Module MPSHIFT

In order to control the program execution, you can use the following keywords within the control file:

$csmp2

Switches on the calculation of the MP2 NMR shieldings. The required SCF shielding step will be performed in the same run. This flag will be set by the script mp2prep.

$traloop n

specifies the number of loops (or 'passes') over occupied orbitals n when doing an MP2 calculation: the more passes the smaller file space requirements--but CPU time will go up. This flag will be set by the script mp2prep.

$mointunit

Scratch file settings for an MP2 calculation. Please refer to Section 15.2.12 for a description of the syntax. This flag will be set by the script mp2prep.

$csconv real

Sets the convergence threshold for the shielding constant of succeeding CPHF iterations. The unit is ppm and the default value is 0.01.

$csconvatom integer

This selects the atom number for convergence check after each cphf iteration. After this convergence is reached all other atoms are checked, too (default: 1).

$thime, $thize, $scftol, $scfintunit, $scfmo

have the save meaning as in dscf (see Section 15.2.5);
Since mpshift works 'semi-direct' it uses the same integral storage.

$scratch files

The scratch files allocated by mpshift can be placed anywhere in your file systems instead of the working directory by referencing their pathnames in this data group. All possible scratch files are listed in the following example:

$scratch files
    mpshift   csssmat         path1/file1
    mpshift   cshsmat         path2/file2
    mpshift   csdgsmat        path3/file3
    mpshift   csusmat         path4/file4
    mpshift   dens            path5/file5
    mpshift   fock            path6/file6
    mpshift   dfock           path7/file7
    mpshift   idvds1          path8/file8
    mpshift   idvds2          path9/file9
    mpshift   idvds3          path10/file10
    mpshift   jdvds1          path11/file11
    mpshift   jdvds2          path12/file12
    mpshift   jdvds3          path13/file13
    mpshift   cshmmat         path14/file14

$trast , $trand traloop-number

stands for traloop start and traloop end. Each loop or pass in MP2 chemical shift calculations can be done individually by providing the keywords $trast and $trand. This can be used to do a simple parallelization of the run:
Create separate inputs for each traloop. Add

    $trast <number>
    $trand <number>

in the control files, number goes from 1 to the number of $traloops. Each calculation will create a restart file called restart.mpshift. To collect all steps and to do the remaining work, copy all restart files to one directory and rename them to restart.mpshift.number, add $trast -1 and $trand number_of_traloops to the control file and start mpshift.