Application of Gaussian-type geminals in local second-order Moller-Plesset perturbation theory

摘要

In this work Gaussian-type Geminals (GTGs) are applied in local second-order Moller-Plesset perturbation theory to improve the basis set convergence.Our implementation is based on the weak orthogonality functional of Szalewicz et al,[Chem.Phys.Lett.91,169 (1982); J.Chem.Phys.78,1420 (1983)] and a newly developed program for calculating the necessary many-electron integrals.The local approximations together with GTGs in the treatment of the correlation energy are introduced and tested.First results for correlation energies of H_2O,CH_4,CO,C_2H_2,C_2H_4,H_2CO,and N_2H_4 as well as some reaction and activation energies are presented.More than 97% of the valence-shell correlation energy is recovered using aug-cc-pVDZ basis sets and six GTGs per electron pair.The results are compared with conventional calculations using correlation-consistent basis sets as well as with MP2-R12 results.