11.1.3 Parameters to enable local fitting

Local fitting as described in H.-J. Werner, F. R. Manby, and P. J. Knowles, J. Chem. Phys. 118, 8149 (2003), Polly, H.-J. Werner, F. R. Manby, and Peter J. Knowles, Mol. Phys. 102, 2311 (2004), and M. Schütz, H.-J. Werner, R. Lindh and F. R. Manby, J. Chem. Phys. 121, 737 (2004). can be activated by setting LOCFIT=1. By default, local fitting is disabled, because under certain circumstances it can lead to unacceptable errors. For instance, local fitting must not be used in counter-poise calculations, since the lack of fitting functions at the dummy atoms can lead to wrong results.

Local fitting can be restricted to certain programs, using the following options:

LOCFIT

If positive, use local fitting in all programs in which it is available (default 0).

LOCFIT_SCF

If positive, use local fitting in SCF (default LOCFIT)

LOCFIT_MP2

If positive, use local fitting in DF-LMP2; 1: use orbital domains; 2: use pair domains (default LOCFIT)

LOCFIT_F12

If positive, use local fitting in DF-LMP2-F12 (default LOCFIT)

LOCFIT_CCSD

If positive, use local fitting in DF-LCCSD (default LOCFIT)

LOCFIT_2EXT

If positive, use local fitting in LCCSD 2ext transformation (default LOCFIT_CCSD)

LOCFIT_3EXT

If positive, use local fitting in LCCSD 3ext transformation (default LOCFIT_CCSD)

LOCFIT_4EXT

If positive, use local fitting in LCCSD 4ext transformation (default LOCFIT_CCSD)

LOCFIT_CPHF

If positive, use local fitting in CPHF (default LOCFIT)

LOCFIT_SCFGRD

If positive, use local fitting in gradient calculations (default LOCFIT)

LOCORB

If positive, use localized orbitals in DF-HF (default 1)

LOCTRA

If positive, use local screening in first half transformation (default LOCFIT).

DSCREEN

If positive, enable density screening in LMP2 (default 0)

KSCREEN

If positive, enable fit-basis Schwarz screening in LMP2 (default depends on LOCTRA).