Journal of Chemical Physics, Vol.100, No.2, 1366-1374, 1994
New Effective Strategy of Generating Gaussian-Type Geminal Basis-Sets for Correlation-Energy Calculations
Gaussian-type geminal basis sets for correlation energy calculations are usually obtained by optimization of the second-order energy functional. In the present work we propose a new strategy of generating the initial sets of geminals for these optimizations. Taking advantage of the information about the analytical structure of the second-order pair functions, this strategy produces reasonable starting values of the nonlinear geminal parameters, which lead to accurate second-order energies after only a short, crude reoptimization.
Keywords:MOLECULAR CORRELATION ENERGIES;PLESSET MP2-R12 CALCULATIONS;CORRELATION CUSP;WAVE-FUNCTIONS;PERTURBATION CALCULATION;DIATOMIC-MOLECULES;NEON ATOM;2ND-ORDER;TERMS;CARE