P(Zij|Ck;dij;αijk;βij;εijk) is the class-conditional prior probability, and using the traditional method to obtain its expression is very difficult. Generally, if a node belongs to a community, the link density between it and the cluster center node of the community is high, otherwise the link density between these nodes is low. That is similar to the interaction force between particles in the electric field, namely the weak force among nodes result in low density and the high force among nodes leads to high density. Accordingly, P(Zij|Ck;dij;αijk;βij;εijk) can be approximately defined by Gaussian potential function (GPF) which is mainly used to describe the interaction force of electric particles, as is shown in Eq 8. P(Zij|Ck;dij;αijk;βij;εijk)=e−dij+βij(αijk+εijk)θ,(8) where the impact factor θ is used to adjust the influence boundary.