Momentum-space properties of N2.

Abstract

Properties that depend on the anisotropy of the electron momentum distribution of ${\mathrm{N}}_{2}$(X ${\mathrm{}}^{1}$${\mathrm{\ensuremath{\Sigma}}}_{\mathrm{g}}^{+}$) have not been determined accurately even by a fairly sophisticated calculation [Phys. Rev. A 34, 4695 (1986)] using a configuration-interaction wave function. This paper reports calculations based on a series of wave functions designed to assess the sensitivity of one-electron momentum-space properties of ${\mathrm{N}}_{2}$ to variations in the treatment of electron correlation and the choice of basis sets of Slater-type functions. The most elaborate of these wave functions, which consists of 169 650 configurations, provides satisfactorily converged predictions of a wide variety of isotropic momentum-space properties as well as directional Compton profiles. However, the anisotropy of the kinetic energy tensor turns out to be so small in magnitude that even its sign remains uncertain.