Computation of large systems with economic basis set: systems involving weak sodium-organic interaction

We show that an economic basis set can describe systems involving sodium-or ganic interaction in ab initio calculations. Basis sets, in which the polar ization and the diffuse functions are considered only for sodium and atoms of strong electronegativity of various Na-containing weakly bound systems, can predict geometric structures, dipole moments and binding energies with negligible basis set superposition error (BSSE), comparable to those using 6-31+G* in calculations with density functional theory. This study is expec ted to provide a general guideline for basis set selection in computations of large systems involving metal-organic interaction. (C) 2000 Elsevier Sci ence B.V. All rights reserved.