H p − − p ′ = Ψ Ψ κ κ p κ κ p ′ κ κ p ″ , α α α α ′ α α ″ Ψ Ψ κ κ p κ κ p ′ κ κ p ″ , α α α α ′ α α ″ = ∑ ∑ i j k ∑ ∑ α α β β γ γ Ψ Ψ i j k , α α β β γ γ s i α α κ κ p s j α α ′ κ κ p ′ s k α α ″ κ κ p ″ ( ⟨ ⟨ m ⟩ ⟩ ω ω κ κ p , α α ) 1 / 2 e x p [ i ( κ κ p ⋅ ⋅ r i + κ κ p ′ ⋅ ⋅ r j + κ κ p ⋅ ⋅ r k ) ] ,