diff --git a/src/tools/MolDataClass.cpp b/src/tools/MolDataClass.cpp
index 009114d01d9beb5d687609f6832ed6fff16d044d..107ed2ee3d5725d2d54308a2f8e92e0da785653c 100644
--- a/src/tools/MolDataClass.cpp
+++ b/src/tools/MolDataClass.cpp
@@ -70,19 +70,35 @@ bool MolDataClass::allowedResidue( const std::string& type, const std::string& r
     else if(residuename=="HSP") return true; // HIS-P charmm
     else return false;
   } else if( type=="dna" ) {
-    if(residuename=="DA") return true;
-    else if(residuename=="DG") return true;
-    else if(residuename=="DT") return true;
-    else if(residuename=="DC") return true;
+    if(residuename=="A") return true;
+    else if(residuename=="A5") return true;
+    else if(residuename=="A3") return true;
+    else if(residuename=="AN") return true;
+    else if(residuename=="G") return true;
+    else if(residuename=="G5") return true;
+    else if(residuename=="G3") return true;
+    else if(residuename=="GN") return true;
+    else if(residuename=="T") return true;
+    else if(residuename=="T5") return true;
+    else if(residuename=="T3") return true;
+    else if(residuename=="TN") return true;
+    else if(residuename=="C") return true;
+    else if(residuename=="C5") return true;
+    else if(residuename=="C3") return true;
+    else if(residuename=="CN") return true;
+    else if(residuename=="DA") return true;
     else if(residuename=="DA5") return true;
     else if(residuename=="DA3") return true;
     else if(residuename=="DAN") return true;
+    else if(residuename=="DG") return true;
     else if(residuename=="DG5") return true;
     else if(residuename=="DG3") return true;
     else if(residuename=="DGN") return true;
+    else if(residuename=="DT") return true;
     else if(residuename=="DT5") return true;
     else if(residuename=="DT3") return true;
     else if(residuename=="DTN") return true;
+    else if(residuename=="DC") return true;
     else if(residuename=="DC5") return true;
     else if(residuename=="DC3") return true;
     else if(residuename=="DCN") return true;