Interelectronic angle densities of atoms in momentum space

Abstract

For the 102 atoms from He to Lr in their ground states, the Hartree–Fock interelectronic angle densities,¯A(¯θ12), in momentum space are reported, where ¯θ12 is the angle between the momentum vectorsp 1 and p 2 of two electrons. In the first three atoms, He–Be, ¯A(¯θ12) is found to be uniform independent of ¯θ12, while in the remaining 99 atoms,¯A(¯θ12) is larger for a large ¯θ12 than for a small ¯θ12. Accordingly, the average interelectronic angles in momentum space are 90° precisely for the three atoms and greater than 90° for the 99 atoms.