Ke. Banyard et J. Sanders, MOMENTUM-SPACE AND COULOMB CORRELATION - A 2-PARTICLE DENSITY ANALYSIS FOR THE H-2(1-SIGMA-G+) MOLECULE, The Journal of chemical physics, 99(7), 1993, pp. 5281-5294
Electron correlation in momentum space is assessed for the ground-stat
e of H2 by examining changes in the two-particle probability density e
valuated over preselected momentum planes. The associated radial and a
ngular ''planar Coulomb shifts,'' DELTAR(p12) and DELTAA(epsilon(p)),
are also calculated. This study complements an earlier analysis for H-
2 in position space. The natural expansion of the correlated wave func
tion used previously was converted into momentum space by means of a D
irac-Fourier transform. As before, correlation effects are measured wi
th respect to the description provided by the first natural configurat
ion. Characteristics of the three components of Coulomb correlation fo
r a linear molecule are highlighted by specific choices for the moment
um of a ''test'' or ''reference'' electron. Unlike position space, it
was found that one component worked in distinct opposition to the othe
r components, a feature analogous to atomic studies in momentum space.
The trends observed throughout a series of probability changes in mom
entum space for H-2 were rationalized and linked to the correlation be
havior in position space.