BASIS-SET MODELING FOR MOLECULAR CALCULATIONS USING EFFECTIVE CORE POTENTIAL

A new approach for developing of basis sets to be used along with effe ctive core potential is systematically studied. The behavior of the LC AO coefficients versus the ln(alpha) of the respective primitives can provide simple guidelines to establish the range over which the basis set should be developed or modified, especially when using effective c ore potential. Double-zeta basis sets were modeled for SBK pseudopoten tial from all-electron basis sets for a series of compounds containing elements of the second period of the periodic table. Application of t he modeled basis sets at the Hartree-Fock and MP2 levels of theory sho ws that the new method provides molecular properties as accurate as th ose calculated by all-electron calculations. (C) 1997 John Wiley & Son s,Inc.