Before starting any energy calculations, the geometry and basis set must be defined in GEOMETRY and BASIS blocks, respectively. By default, two electron integrals are evaluated once and stored on disk. This behaviour may be overridden by using the input command gdirect to force evaluation of integrals on the fly. MOLPRO checks if the one-and two-electron integrals are available for the current basis set and geometry, automatically computing them if necessary. The program also recognizes automatically if only the nuclear charges have been changed, as is the case in counterpoise calculations. In this case, the two-electron integrals are not recomputed.


molpro@molpro.net 2019-01-15