diff --git a/src/USER-EFF/atom_vec_electron.cpp b/src/USER-EFF/atom_vec_electron.cpp
index 15de2e1a84585b0762361391fb11bf956a6514e2..c54fa8cbb46851bc1903ae77ef3da1bf934bc099 100644
--- a/src/USER-EFF/atom_vec_electron.cpp
+++ b/src/USER-EFF/atom_vec_electron.cpp
@@ -793,23 +793,23 @@ int AtomVecElectron::data_vel_hybrid(int m, char **values)
    return # of bytes of allocated memory 
 ------------------------------------------------------------------------- */
 
-double AtomVecElectron::memory_usage()
+bigint AtomVecElectron::memory_usage()
 {
-  double bytes = 0.0;
-  
-  if (atom->memcheck("tag")) bytes += nmax * sizeof(int);
-  if (atom->memcheck("type")) bytes += nmax * sizeof(int);
-  if (atom->memcheck("mask")) bytes += nmax * sizeof(int);
-  if (atom->memcheck("image")) bytes += nmax * sizeof(int);
-  if (atom->memcheck("x")) bytes += nmax*3 * sizeof(double);
-  if (atom->memcheck("v")) bytes += nmax*3 * sizeof(double);
-  if (atom->memcheck("f")) bytes += nmax*3 * sizeof(double);
-  
-  if (atom->memcheck("q")) bytes += nmax * sizeof(double);
-  if (atom->memcheck("spin")) bytes += nmax * sizeof(int);
-  if (atom->memcheck("eradius")) bytes += nmax * sizeof(double);
-  if (atom->memcheck("ervel")) bytes += nmax * sizeof(double);
-  if (atom->memcheck("erforce")) bytes += nmax * sizeof(double);
+  bigint bytes = 0;
+  
+  if (atom->memcheck("tag")) bytes += memory->usage(tag,nmax);
+  if (atom->memcheck("type")) bytes += memory->usage(type,nmax);
+  if (atom->memcheck("mask")) bytes += memory->usage(mask,nmax);
+  if (atom->memcheck("image")) bytes += memory->usage(image,nmax);
+  if (atom->memcheck("x")) bytes += memory->usage(x,nmax,3);
+  if (atom->memcheck("v")) bytes += memory->usage(v,nmax,3);
+  if (atom->memcheck("f")) bytes += memory->usage(f,nmax,3);
+  
+  if (atom->memcheck("q")) bytes += memory->usage(q,nmax);
+  if (atom->memcheck("spin")) bytes += memory->usage(spin,nmax);
+  if (atom->memcheck("eradius")) bytes += memory->usage(eradius,nmax);
+  if (atom->memcheck("ervel")) bytes += memory->usage(ervel,nmax);
+  if (atom->memcheck("erforce")) bytes += memory->usage(erforce,nmax);
   
   return bytes;
 }
diff --git a/src/USER-EFF/atom_vec_electron.h b/src/USER-EFF/atom_vec_electron.h
index 704a8378feeccc8bf0a7f442ad42e195767e6f3e..3670958c16a41f80fec8f035d808d5d40ee67837 100644
--- a/src/USER-EFF/atom_vec_electron.h
+++ b/src/USER-EFF/atom_vec_electron.h
@@ -57,7 +57,7 @@ class AtomVecElectron : public AtomVec {
   int data_atom_hybrid(int, char **);
   void data_vel(int, char **);
   int data_vel_hybrid(int, char **);
-  double memory_usage();
+  bigint memory_usage();
   
  private:
   double PI;
@@ -71,4 +71,3 @@ class AtomVecElectron : public AtomVec {
 
 #endif
 #endif
-