diff --git a/qpms/groups.h b/qpms/groups.h
index 96f9faa..b1198b7 100644
--- a/qpms/groups.h
+++ b/qpms/groups.h
@@ -43,9 +43,10 @@ struct qpms_irot3_t;
  */
 typedef struct qpms_finite_group_t {
 	char *name;
-	size_t order; ///< Group order (number of elements)
+	qpms_gmi_t order; ///< Group order (number of elements)
 	qpms_gmi_t idi; ///< Identity element index
 	qpms_gmi_t *mt; ///< Group multiplication table. If c = a*b, then ic = mt[order * ia + ib].
+	qpms_gmi_t *invi; ///< Group elem inverse indices.
 	qpms_gmi_t *gens; ///< A canonical set of group generators.
 	int ngens; ///< Number of the generators in gens;
 	qpms_permutation_t permrep[]; ///< Permutation representations of the elements.
diff --git a/qpms/symmetries.py b/qpms/symmetries.py
index 906a2e4..cd9f959 100644
--- a/qpms/symmetries.py
+++ b/qpms/symmetries.py
@@ -103,6 +103,10 @@ class SVWFPointGroupInfo: # only for point groups, coz in svwf_rep() I use I_tyt
             ss = ', '.join([str(permindices[permlist[i]*permlist[j]]) for j in range(order)])
             s += '    ' + ss + ',\n'
         s += '  },\n'
+        # qpms_gmi_t *invi
+        s += '  { // invi\n'
+        s += '    ' + ', '.join([str(permindices[permlist[j]**-1]) for j in range(order)])
+        s += '\n  },\n'
         # qpms_gmi_t *gens
         s += '  {' + ', '.join([str(permindices[g]) for g in self.permgroupgens]) + '}, // gens\n'
         # int ngens
@@ -111,7 +115,7 @@ class SVWFPointGroupInfo: # only for point groups, coz in svwf_rep() I use I_tyt
         s += '  { // permrep\n'
         for i in range(order):
             s += '    "%s",\n' % str(permlist[i])
-        s += '  }\n'
+        s += '  },\n'
         # char **elemlabels
         s += '  NULL, // elemlabels\n'
         # int permrep_nelem