The averages of the fine structure interaction operators for the high-L^R Rydberg states of the diatomic molecules

The averages of the electric and magnetic fine structure interaction operators for the nonpenetrating Rydberg states in diatomic molecules for four different Hund coupling d cases are obtained. A method which allows the author to avoid operations with the nondiagonal matrix elements is used. It is shown that in the d cases the differences between the levels of the electric fine structure satisfy the rule Delta E=E_N+1^EFS-E_N^EFS=G₁(N+1)³-G₂(N+1), where N is the total momentum without the spin and G₁ and G₂ are constants. It is shown that the recent experimental data for H₂, He₂ and NO are in good agreement with the theoretical results.