diff --git a/src/other.jl b/src/other.jl
index 7ec0592..a201c57 100644
--- a/src/other.jl
+++ b/src/other.jl
@@ -32,26 +32,30 @@ function PeriodicGraphs.make_supercell(cell::Cell{T}, t) where T
             cell.mat[1,3]*t3, cell.mat[2,3]*t3, cell.mat[3,3]*t3,
         )
         n = length(cell.equivalents)
-        newequivalents = Vector{EquivalentPosition{T}}(undef, n + (n+1)*(prod(t)-1))
-        it1, it2, it3 = 1//t1, 1//t2, 1//t3
-        for (i, eq) in enumerate(cell.equivalents)
-            newequivalents[i] = EquivalentPosition(SMatrix{3,3,T,9}(
-                eq.mat[1,1],        eq.mat[2,1]*t1*it2, eq.mat[3,1]*t1*it3,
-                eq.mat[1,2]*t2*it1, eq.mat[2,2],        eq.mat[3,2]*t2*it3,
-                eq.mat[1,3]*t3*it1, eq.mat[2,3]*t3*it2, eq.mat[3,3]
-            ), SVector{3,T}(eq.ofs[1]*it1, eq.ofs[2]*it2, eq.ofs[3]*it3))
-        end
-        for (j, (a, b, c)) in enumerate(PeriodicGraphs.MetaClock(t))
-            a == b == c == 0 && continue
-            ofs = (j-1)*(n+1)
-            trans = SVector{3,T}(a*it1, b*it2, c*it3)
-            newequivalents[ofs] = EquivalentPosition(one(SMatrix{3,3,T,9}), trans)
-            for i in 1:n
-                ref = newequivalents[i]
-                newequivalents[ofs+i] = EquivalentPosition(ref.mat, ref.ofs + trans)
+        if n == 0
+            newmat, EquivalentPosition{T}[]
+        else
+            newequivalents = Vector{EquivalentPosition{T}}(undef, n + (n+1)*(prod(t)-1))
+            it1, it2, it3 = 1//t1, 1//t2, 1//t3
+            for (i, eq) in enumerate(cell.equivalents)
+                newequivalents[i] = EquivalentPosition(SMatrix{3,3,T,9}(
+                    eq.mat[1,1],        eq.mat[2,1]*t1*it2, eq.mat[3,1]*t1*it3,
+                    eq.mat[1,2]*t2*it1, eq.mat[2,2],        eq.mat[3,2]*t2*it3,
+                    eq.mat[1,3]*t3*it1, eq.mat[2,3]*t3*it2, eq.mat[3,3]
+                ), SVector{3,T}(eq.ofs[1]*it1, eq.ofs[2]*it2, eq.ofs[3]*it3))
+            end
+            for (j, (a, b, c)) in enumerate(PeriodicGraphs.MetaClock(t))
+                a == b == c == 0 && continue
+                ofs = (j-1)*(n+1)
+                trans = SVector{3,T}(a*it1, b*it2, c*it3)
+                newequivalents[ofs] = EquivalentPosition(one(SMatrix{3,3,T,9}), trans)
+                for i in 1:n
+                    ref = newequivalents[i]
+                    newequivalents[ofs+i] = EquivalentPosition(ref.mat, ref.ofs + trans)
+                end
             end
+            newmat, newequivalents
         end
-        newmat, newequivalents
     end
     Cell{T}(cell.hall, newmat, newequivalents)
 end
diff --git a/src/types.jl b/src/types.jl
index 56b5406..6a65b04 100644
--- a/src/types.jl
+++ b/src/types.jl
@@ -40,6 +40,14 @@ end
 (eq::EquivalentPosition)(x) = muladd(eq.mat, x, eq.ofs)
 EquivalentPosition{T}() where T = EquivalentPosition{T}(one(SMatrix{3,3,T,9}), zero(SVector{3,T}))
 
+function EquivalentPosition(mat::AbstractMatrix{T}, ofs::AbstractVector{U}) where {T,U}
+    S = promote_type(T,U)
+    EquivalentPosition{S}(SMatrix{3,3,S,9}(mat), SVector{3,S}(ofs))
+end
+function EquivalentPosition{T}(eq::EquivalentPosition{S}) where {S,T}
+    EquivalentPosition{T}(SMatrix{3,3,T,9}(eq.mat), SVector{3,T}(eq.ofs))
+end
+
 """
     find_refid(eqs)