Prop Keyword
Last Update:
12/31/2000
DESCRIPTION
This properties keyword tells Gaussian 98 to compute electrostatic properties [266]. By default, the potential, electric field, and electric field gradient at each nucleus are computed. The density used for the electrostatic analysis is controlled by the Density keyword.
PROPERTY SELECTION OPTIONS
EFG
Specifies that potential, field and field gradient
are to be computed. This is the default.
Potential
Specifies that the potential but not the
field or field gradient are to be computed. NoPotential suppresses
computation of the electric potential and higher properties.
Field
Specifies that the potential and field, but not
the field gradient, are to be computed.
EPR
Compute the anisotropic hyperfine coupling constants
[274, 381, 382].
INPUT SOURCE-RELATED OPTIONS
If both Read and Opt are specified, the order of the input sections is fixed points (Read), then optimized points (Opt).
Read
Causes the program to read a list of additional
centers at which properties will be computed from the input stream. The
Cartesian coordinates of each center in angstroms are read in free field, with
one center per line, in the standard orientation.
Opt
Causes the program to read a list of centers as in
Prop=Read, but then to locate the minimum in the electric potential
closest to each specified point.
FitCharge
Fit atomic charges to the electrostatic
potential at the Van der Waals surface.
Dipole
Constrain fitted charges to the dipole moment.
Grid
Specifies that the potential is to be calculated
at one or more grids of points (generally superceded by Cube=Potential).
This option requests mapping of the electric potential over a 2D grid of
points. The points can either be specified as a uniform rectangular grid or, as
an arbitrary collection read from an auxiliary file (both described below), or
via the input format used by Cube=Potential
Three additional input lines are required for a uniform grid:
KTape,XO,YO,ZO The Fortran unit to which to write the map, and the coordinates of the map's lower left corner.
N1,X1,Y1,Z1 The number of rows in the grid, and the vertical step size.
N2,X2,Y2,Z2 The number of columns in the grid, and the horizontal step size.
For points read from an auxillary file, a single line of input supplies all of the necessary information:
N,NEFG,LTape,KTape
The coordinates of N points in Angstroms will be read from unit LTape, in format 3F20.12. LTape defaults to 52. The potential (NEFG=3), potential and field (NEFG=2), or potential, field, and field gradient (NEFG=1) will be computed and written to unit KTape. For example, the following input indicates that 19,696 points for the electrostatic potential (code 3) will be read from Fortran unit 10, with output written to Fortran unit 11:
19696,3,10,11
AVAILABILITY
HF, all DFT methods, CIS, MP2, MP3, MP4(SDQ), CID, CISD, CCD, and QCISD.
RELATED KEYWORDS