This keyword allows to specify which set of Repulsion Atomic Parameters has to be used for calculation of atomatom exchangerepulsion interaction energies.
The following sets are available:
 Original Spackman's Atomic Parameters, SAP's (Spackman, 1986)
 Scaled SAP's to fit ZieglerRauk ADFBLYP/TZP repulsion energies.
 Leastsquares refined AP's, which fit ZieglerRauk ADFBLYP/TZP repulsion energies. Available for H, C, N, O and S. For the remaining atoms, option 2 is adopted.
 Scaled SAP's to fit KitauraMorokuma GAMESSHF/631G(d) repulsion energies.
 Leastsquares refined AP's, which fit KitauraMorokuma GAMESSHF/631G(d) repulsion energies. Available for H, C, N and O. For atom S the value of option 3 is adopted. For the remaining atoms, option 4 is adopted.
Option 5 is the default.
