1 3 2

$S_1{S}_3{S}_2=2\to \langle VPV{P}^{2}V{P}^{2}V\rangle \Delta E_2\Delta E_1$

(1)

$\to -\langle VPV{P}^{3}V{P}^{2}V\rangle {\left(\Delta E_1\right)}^3$

(1)

1 2 3

$S_1{S}_2{S}_3=2\to \langle VPV{P}^{2}V{P}^{2}V\rangle \Delta E_1\Delta E_2$

(1)

$\to -\langle VPV{P}^{2}V{P}^{3}V\rangle {\left(\Delta E_1\right)}^3$

(1)

3 3

$S_3{S}_3=4\to \langle V{P}^{2}V{P}^{2}V\rangle {\left(\Delta E_2\right)}^2$

(1)

$\to -\langle V{P}^{3}V{P}^{2}V\rangle {\left(\Delta E_1\right)}^2\Delta E_2$

(1)

$\to -\langle V{P}^{2}V{P}^{3}V\rangle \Delta E_2{\left(\Delta E_1\right)}^2$

(1)

$\to \langle V{P}^{3}V{P}^{3}V\rangle {\left(\Delta E_1\right)}^4$

(1)