Orbital-Based Interpretation of Electron Density Differences in Ne_2 and Polarized Ne and Ne~(6+)

摘要

Total and orbital density difference contours have been calculated from Hartree-Fock wave functions (uncontracted 14s9p4d3f basis) for three systems: Ne and Ne~(6+) polarized by a +1 charge at 4.66 bohr and Ne_2 (R = 3.80 bohr). Effects of MP2 correlation corrections are found to be negligible. In Ne, the outer portion of every orbital is polarized toward the _1 charge. The hybrid [2s + (0.0096)2ps_z] is an excellent approximation to this system's 2s orbital, whose density difference reverses polarity within its circular node. Farther out, a large intermediate region of the 2p#sigma# orbital is also polarized away from the +1 charge. In Ne_2, only 1s and 2s densities show dipolar polarization: the 2s toward the other nucleus due to 2p#sigma# electron depletion in the atom-overlap region; the 1s in the opposite direction due to the 2s field. The latter effect is also observed in polarized Ne~(6+). The total Ne_2 density difference exhibits atomic quadrupolar polarization due to unpolarized 2p#sigma# density buildup and 2p#pi# depletion.