Atomic radial grid

For each atom the charge densities and the coulomb potentials of frozen core and valence electrons are computed in a radial grid and stored on TAPE21. The values in the points of the molecular numerical integration grid are then evaluated by interpolation from the table of radial values.

The radial grid consists of a sequence of r-values, defined by a smallest value, a constant multiplication factor to obtain each successive r-value, and the total number of points. Equivalently it can be characterized by the smallest r-value, the largest r-value, and the number of points; from these data the program computes then the constant multiplication factor. The characteristics are set with

RADIALCOREGRID {nrad=points} {rmin=rmin} {rmax=rmax}

points

The number of radial grid points; default: 5000.

rmin

The shortest distance used in the radial grid; default 1e-6 Angstrom

rmax

The largest distance in the radial grid; default: 100 Angstrom.

rmin and rmax, when specified, are interpreted as specified in units of length defined by units.

The keyword name radialcoregrid has historical reasons: in earlier releases the radial grid was used only for the frozen core density and potential.