I did a NBO calculation on molecule having Ge and N atom . I want to study donation of lone pair of N to empty orbital of Ge. Second Order Perturbation Theory Analysis of Fock Matrix in NBO Basis show following output related to this
Donor NBO (i) Acceptor NBO (j) E(2)
162. LP ( 1) N 4 /158. LP*( 2)Ge 1 1.44
162. LP ( 1) N 4 /159. LP*( 3)Ge 1 2.21
163. LP ( 2) N 4 /158. LP*( 2)Ge 1 92.40
163. LP ( 2) N 4 /159. LP*( 3)Ge 1 41.75
There is only one lone pair on N and an empty orbital on Ge ,So, I'm confused why it's show four type of interaction.