Bug fix for potential enegry

common.jl

@@ -90,6 +90,7 @@ function calculate_Vs(s::system{T}, V_twobody::Function, ϕ::T, n_image::Int)::A
                 end
             end
         end
+        Vs[i] *= s.multiplicity[i[1]]^2
     end
     return Vs
 end