Relativistic Gaussian functions for atoms by fitting numerical results with adaptive nonlinear least‐square algorithm

Abstract

The relativistic Gaussian basis set of Hg has been obtained by fitting the numerical relativistic atomic radial wave functions with the adaptive nonlinear least‐square algorithm combined with the subset selection method. This fitting procedure and fitted results are presented. From this basis, in a further several‐step procedure, we generated a new basis that gave reasonably good results for Hg, HgO, and a Se atom chain, respectively. The original fitted basis did not work, because the resulting overlap matrix was not positive definite. ©1999 John Wiley & Sons, Inc. J Comput Chem 20: 655–664, 1999