diff --git a/common.jl b/common.jl
index 672551f..bb02b7b 100644
--- a/common.jl
+++ b/common.jl
@@ -90,7 +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]]
+        Vs[i] *= s.multiplicity[s.unique_i[i[1]]]
     end
     return Vs
 end