A priori estimation of the nodal surfaces of trial wave functions of lithium atom

Abstract

Some aspects of geometric interpretation of the Pauli exclusion principle in the Hartree—Fock approximation and in the framework of the many-electron wave function (MWF) method developed by the authors are discussed taking the Li (2S) ground electronic state as an example. Arguments are brought forward that indicate insufficient adequacy of the Hartree—Fock approximation for a priori estimation of the MWF nodal surfaces. It was pointed that, unlike the MWF method, the Hartree—Fock approximation can not describe the dependence of the shape of the MWF nodal surfaces on the nuclear charge of Li atom and on electron-electron correlation effects.