13.2 Intracules

13.2.4 Intracule Job Control

(June 30, 2021)

The following $rem variables can be used to control the calculation of intracules.

INTRACULE
       Controls whether intracule properties are calculated (see also the $intracule section).
TYPE:
       LOGICAL
DEFAULT:
       FALSE
OPTIONS:
       FALSE No intracule properties. TRUE Evaluate intracule properties.
RECOMMENDATION:
       None

WIG_MEM
       Reduce memory required in the evaluation of W(u,v).
TYPE:
       LOGICAL
DEFAULT:
       FALSE
OPTIONS:
       FALSE Do not use low memory option. TRUE Use low memory option.
RECOMMENDATION:
       The low memory option is slower, so use the default unless memory is limited.

WIG_LEB
       Use Lebedev quadrature to evaluate Wigner integrals.
TYPE:
       LOGICAL
DEFAULT:
       FALSE
OPTIONS:
       FALSE Evaluate Wigner integrals through series summation. TRUE Use quadrature for Wigner integrals.
RECOMMENDATION:
       None

WIG_GRID
       Specify angular Lebedev grid for Wigner intracule calculations.
TYPE:
       INTEGER
DEFAULT:
       194
OPTIONS:
       Lebedev grids up to 5810 points.
RECOMMENDATION:
       Larger grids if high accuracy required.

N_WIG_SERIES
       Sets summation limit for Wigner integrals.
TYPE:
       INTEGER
DEFAULT:
       10
OPTIONS:
       n<100
RECOMMENDATION:
       Increase n for greater accuracy.

N_I_SERIES
       Sets summation limit for series expansion evaluation of in(x).
TYPE:
       INTEGER
DEFAULT:
       40
OPTIONS:
       n>0
RECOMMENDATION:
       Lower values speed up the calculation, but may affect accuracy.

N_J_SERIES
       Sets summation limit for series expansion evaluation of jn(x).
TYPE:
       INTEGER
DEFAULT:
       40
OPTIONS:
       n>0
RECOMMENDATION:
       Lower values speed up the calculation, but may affect accuracy.