Premium
Application of L öwdin's canonical orthogonalization method to the S later‐type orbital configuration‐interaction basis set
Author(s) -
Jiao Li Guang,
Ho Yew Kam
Publication year - 2015
Publication title -
international journal of quantum chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.484
H-Index - 105
eISSN - 1097-461X
pISSN - 0020-7608
DOI - 10.1002/qua.24867
Subject(s) - orthogonalization , basis set , basis (linear algebra) , basis function , configuration interaction , computation , wave function , slater determinant , excited state , sto ng basis sets , dimension (graph theory) , set (abstract data type) , atom (system on chip) , curse of dimensionality , mathematics , quantum mechanics , electron , physics , atomic orbital , algorithm , computer science , geometry , complete active space , combinatorics , density functional theory , statistics , embedded system , programming language
We apply Löwdin's canonical orthogonalization method to investigate the linearly dependent problem arising from the variational calculation of atomic systems using Slater‐type orbital configuration‐interaction (STO‐CI) basis functions. With a specific arithmetic precision used in numerical computations, the nonorthogonal STO‐CI basis is easily linearly dependent when the number of basis functions is sufficiently large. We show that Löwdin's canonical orthogonalization method can successfully overcome such problem and simultaneously reduce the dimension of basis set. This is illustrated first through an S‐wave model He atom, and then the real two‐electron atoms in both the ground and excited states. In all of these calculations, the variational bound state energies of the two‐electron systems are obtained in reasonably high accuracy using over‐redundant STO‐CI bases, however, without using extended high‐precision technique. © 2015 Wiley Periodicals, Inc.