On the Use of an Interpolation Approach for the Choice of Gaussian Polarization Functions

Fernando Ratuchne,Ricardo Celeste,Ana Mora,Albérico Da Silva

doi:10.21577/0103-5053.20180168

Abstract

In this work, we tested a linear interpolation approach in order to select polarization functions (exponents) to be used with Gaussian basis sets. The Gaussian primitive functions were generated here for Ga to Kr and also for Sc to Cu. The general contraction method was used for the construction of contracted Gaussian basis sets of 6Z and 7Z quality. Polarization functions were added to the contracted bases by explicit optimization and also by interpolation of exponents. The performance of the contracted basis sets, augmented with polarization functions obtained by interpolation, was tested with molecular configurations interaction single and double excitations (CISD) and density functional theory (DFT) calculations for the systems Se, Se2, Se6, Ge2, CrH and FeH. The outcomes obtained in this work with interpolated polarization functions agreed very well with the ones augmented with polarization functions obtained by explicit optimization. The interpolation methodology presented here is useful to generate polarization functions for any Gaussian basis set in different series of atoms of the periodic table.

Highlights

In 1986, Mohallem et al.[1] introduced in the scientific literature the so-called generator coordinate Hartree-Fock (GCHF) method
To the original GCHF method,[21] a version developed by Jorge and de Castro,[24] named improved generator coordinate Hartree-Fock (IGCHF) method, in which the space Ω is discretized for each orbital symmetry by using two or three independent arithmetic sequences, was used in the generation of Gaussian basis sets for the atoms of the periodic table.[25,26,27,28]
We are going to present molecular property results for molecules containing atoms of the 3d series of the transition metals using polynomial generator coordinate Gaussian basis sets augmented with polarization functions obtained by interpolation

Summary

Introduction

In 1986, Mohallem et al.[1] introduced in the scientific literature the so-called generator coordinate Hartree-Fock (GCHF) method. In 2003, Barbosa and da Silva[7] modified the way of solving the integral equations of the GCHF method with the aim to generate more flexible Gaussian basis sets to be used in atomic and molecular calculation. In 2015, the first set of primitive (extended) Gaussian basis sets, for the atoms from hydrogen (H) to barium (Ba), that is from Z = 1 to 56, was presented in the literature by employing the new way to discretize the integral equations of the GCHF method by using a polynomial.[8].

Methods

Results

Conclusion