Neglect of four- and approximation of one-, two-, and three-center two-electron integrals in a symmetrically orthogonalized basis |
| |
Authors: | Laikov Dimitri N |
| |
Affiliation: | Department of Physics, AlbaNova University Center, Stockholm University, SE-10691 Stockholm, Sweden. laikov@physto.se |
| |
Abstract: | A new integral approximation for use in molecular electronic structure calculations is proposed as an alternative to the traditional neglect of diatomic differential overlap models. The similarity between the symmetrically orthogonalized and the original basis functions (assumed orthonormal within each atomic set but nonorthogonal between different centers) is used to construct a robust approximation for the two-electron integrals, with the error being quadratic in the deviation between the products of the functions. Invariance properties of this procedure are rigorously proved. Numerical studies on a representative set of molecules at valence-only minimal basis Hartree-Fock level show that the approximation introduces relatively small errors, encouraging its future application in the semiempirical field. |
| |
Keywords: | integral approximation symmetric orthogonalization semiemperical methods differential overlap |
本文献已被 PubMed 等数据库收录! |
|