Anisotropic intracule densities and electron correlation in H2: a quantum Monte Carlo study.
We derive efficient quantum Monte Carlo estimators for the anisotropic intracule and extracule densities. These estimators are used in conjunction with an accurate explicitly correlated wave function to investigate the bond-length dependence of electron correlation effects in the ground-state H(2) molecule. It is shown that the localized increase in the magnitude of the correlation energy as the bond is stretched is accompanied by highly anisotropic correlation effects. In addition, we find a small long-range part of the Coulomb hole, which is present even at the equilibrium bond length.
Applied Physics, School of Applied Sciences, RMIT University, G.P.O. Box 2476V, Melbourne, Victoria 3001, Australia. manolo.per@rmit.edu.au
Manolo C
MC
Per
Salvy P
SP
Russo
Ian K
IK
Snook