diff --git a/doc/src/variable.rst b/doc/src/variable.rst
index 31338279ea..8bd33218ac 100644
--- a/doc/src/variable.rst
+++ b/doc/src/variable.rst
@@ -69,7 +69,7 @@ Syntax
          special functions = sum(x), min(x), max(x), ave(x), trap(x), slope(x), gmask(x), rmask(x), grmask(x,y), next(x), is_file(name), is_os(name), extract_setting(name), label2type(kind,label)
          feature functions = is_active(category,feature), is_available(category,feature), is_defined(category,id)
          atom value = id[i], mass[i], type[i], mol[i], x[i], y[i], z[i], vx[i], vy[i], vz[i], fx[i], fy[i], fz[i], q[i]
-         atom vector = id, mass, type, mol, x, y, z, vx, vy, vz, fx, fy, fz, q
+         atom vector = id, mass, type, mol, radius, q, x, y, z, vx, vy, vz, fx, fy, fz
          compute references = c_ID, c_ID[i], c_ID[i][j], C_ID, C_ID[i]
          fix references = f_ID, f_ID[i], f_ID[i][j], F_ID, F_ID[i]
          variable references = v_name, v_name[i]
diff --git a/src/variable.cpp b/src/variable.cpp
index 19aed73734..b9b3661af8 100644
--- a/src/variable.cpp
+++ b/src/variable.cpp
@@ -4563,6 +4563,7 @@ int Variable::is_atom_vector(char *word)
   if (strcmp(word,"id") == 0) return 1;
   if (strcmp(word,"mass") == 0) return 1;
   if (strcmp(word,"type") == 0) return 1;
+  if (strcmp(word,"radius") == 0) return 1;
   if (strcmp(word,"mol") == 0) return 1;
   if (strcmp(word,"x") == 0) return 1;
   if (strcmp(word,"y") == 0) return 1;
@@ -4621,7 +4622,7 @@ void Variable::atom_vector(char *word, Tree **tree, Tree **treestack, int &ntree
 
   } else if (strcmp(word,"mol") == 0) {
     if (!atom->molecule_flag)
-      error->one(FLERR,"Variable uses atom property that isn't allocated");
+      error->one(FLERR,"Variable uses atom property 'mol' that isn't allocated");
     if (sizeof(tagint) == sizeof(smallint)) {
       newtree->type = INTARRAY;
       newtree->iarray = (int *) atom->molecule;
@@ -4630,6 +4631,18 @@ void Variable::atom_vector(char *word, Tree **tree, Tree **treestack, int &ntree
       newtree->barray = (bigint *) atom->molecule;
     }
     newtree->nstride = 1;
+
+  } else if (strcmp(word,"radius") == 0) {
+    if (!atom->radius_flag)
+      error->one(FLERR,"Variable uses atom property 'radius' that isn't allocated");
+    newtree->array = atom->radius;
+    newtree->nstride = 1;
+
+  } else if (strcmp(word,"q") == 0) {
+    if (!atom->q_flag)
+      error->one(FLERR,"Variable uses atom property 'q' that isn't allocated");
+    newtree->array = atom->q;
+    newtree->nstride = 1;
   }
 
   else if (strcmp(word,"x") == 0) newtree->array = &atom->x[0][0];
@@ -4641,11 +4654,6 @@ void Variable::atom_vector(char *word, Tree **tree, Tree **treestack, int &ntree
   else if (strcmp(word,"fx") == 0) newtree->array = &atom->f[0][0];
   else if (strcmp(word,"fy") == 0) newtree->array = &atom->f[0][1];
   else if (strcmp(word,"fz") == 0) newtree->array = &atom->f[0][2];
-
-  else if (strcmp(word,"q") == 0) {
-    newtree->nstride = 1;
-    newtree->array = atom->q;
-  }
 }
 
 /* ----------------------------------------------------------------------