Correlated Monte Carlo electron-pair density for the atoms helium to neon

Abstract

The Monte Carlo method to obtain the electron-pair density for the atoms helium to neon has been applied. The wave functions of Schmidt and Moskowitz [J. Chem. Phys. 93, 4172 (1990)] to take into account the dynamic correlation among the electrons have been used. For the atoms Be, B and C we have considered the nondynamic correlation due to the near degeneracy 2s−2p by means of a configuration interaction wave function and for Li and Be we have also varied the central part of the wave function. A study of the differences between the correlated and the Hartree–Fock results has been carried out. Finally we have also calculated the interelectronic moments, 〈r12n〉, and the value of the electron pair density at the coalescence point for all the atoms considered.