By default, the numerical step sizes are 0.01 bohr for distances or Cartesian coordinates, and 1 degree for angles. These defaults can be changed using
RSTEP,dr
ASTEP,da
where dr is the displacement for distances (or Cartesian coordinates) in bohr, and da is the displacement for angles in degree. The value of RSTEP is used for symmetrical displacements. The step sizes for individual variables can be modified using
VARSTEP,varname=value,...
where the value must be in atomic units for distances and in degree for angles.