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 vectorsp₁ and p₂ 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.