Subshell-pair interelectronic angles of atoms

Abstract

For the 102 atoms from He to Lr in their ground states, the average interelectronic angles nl,n′l ′‘between an electron in a subshell nl and another electron in a subshell n′l′ are examined, where n and l are the principal and azimuthal quantum numbers, respectively. Theoretical study clarifies that nl,n′l′ are 90° precisely if ∣l−l′∣ are even, while they are larger than 90° if ∣l−l′∣ are odd. Numerical analysis of 3,275 subshell pairs with odd ∣l−l′∣ of the 102 atoms shows that the increases in the total average interelectronic angles from 90° are attributed predominantly to subshell pairs with n=n′ and ∣l−l′∣=1.