$INTGRL

$INTGRL group (optional)

This group controls AO integral formats. It should probably never be given, as the program always picks sensible values.

SCHWRZ
= a flag to activate use of the Schwarz inequality to predetermine small integrals. There is no loss of accuracy when choosing this option, and there are appreciable time savings for bigger molecules. Default=.TRUE. for over 5 atoms, or for direct SCF, and is .FALSE. otherwise.

NOPK
= 0 PK integral option on (default for -RHF-, -UHF-, -ROHF-, -GVB-)

= 1 PK option off (default for -CI- or -MCSCF-, or for any MP2, analytic hessian, etc. run)

= 0 (default)

= 1 Sort integrals into canonical order. There is little point in selecting this option, as no part of GAMESS requires ordered integrals. See also NSQUAR.

NINTMX
= Maximum no. of integrals in a record block. (default = 15000 for P file, = 10000 for PK)

The following parameters control the integral sort. (values given are defaults)

NSQUAR
= 0 Sorted integrals will be in triangular canonical order (default)

= 1 instead sort to square canonical order.

NDAR
= Number of direct access logical records to be used for the integral sort (default=2000)

LDAR
= Length of direct access records (site dependent)

NBOXMX
= 200 Maximum number of bins.

NWORD
= 0 Memory to be used (default=all of it).

NOMEM
= 0 If non-zero, force external sort.

The following parameters control integral restarts (values given are defaults)

           IST=    1      JST=    1    KST=    1    LST=    1
           NREC=   1      INTLOC= 1
 

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