Index: src/UIElements/Views/Qt4/MoleculeList/QtMoleculeItem.cpp
===================================================================
--- src/UIElements/Views/Qt4/MoleculeList/QtMoleculeItem.cpp	(revision 97445f1edda30c6d17472c562f9832a49df3e644)
+++ src/UIElements/Views/Qt4/MoleculeList/QtMoleculeItem.cpp	(revision 63fb7a963007e0f94b955d96ca949cd435eacb2a)
@@ -71,5 +71,6 @@
 void QtMoleculeItem::signOnToMolecule()
 {
-  const molecule *mol = World::getInstance().getMolecule(MoleculeById(molid));
+  const molecule * const mol = const_cast<const World &>(World::getInstance()).
+      getMolecule(MoleculeById(molid));
   if (mol != NULL) {
     if (!IsSignedOn)
@@ -83,5 +84,6 @@
 void QtMoleculeItem::signOffFromMolecule()
 {
-  const molecule *mol = World::getInstance().getMolecule(MoleculeById(molid));
+  const molecule * const mol = const_cast<const World &>(World::getInstance()).
+      getMolecule(MoleculeById(molid));
   if (mol != NULL) {
     if (IsSignedOn)
@@ -140,5 +142,5 @@
 const molecule * const QtMoleculeItem::getMolecule() const
 {
-  const molecule * mol = World::getInstance().getMolecule(MoleculeById(molid));
+  const molecule * const mol = const_cast<const World &>(World::getInstance()).getMolecule(MoleculeById(molid));
   ASSERT (mol != NULL,
       "QtMoleculeItem::getMolecule() - mol with "+toString(molid)+" is gone.");
Index: src/UIElements/Views/Qt4/MoleculeList/QtMoleculeList.cpp
===================================================================
--- src/UIElements/Views/Qt4/MoleculeList/QtMoleculeList.cpp	(revision 97445f1edda30c6d17472c562f9832a49df3e644)
+++ src/UIElements/Views/Qt4/MoleculeList/QtMoleculeList.cpp	(revision 63fb7a963007e0f94b955d96ca949cd435eacb2a)
@@ -578,5 +578,6 @@
             QtMoleculeItemFactory::NAME));
     const moleculeId_t molid = ItemToMoleculeId(_item);
-    const molecule *mol = World::getInstance().getMolecule(MoleculeById(molid));
+    const molecule *mol = const_cast<const World &>(World::getInstance()).
+        getMolecule(MoleculeById(molid));
     if (std::binary_search(
             toBeRemovedItems_copy.begin(), toBeRemovedItems_copy.end(),
@@ -624,6 +625,6 @@
 //    LOG(1, "Adding molecule " << (*moliter)->getName());
     // check that World knows the molecule still
-    const molecule * const mol =
-        World::getInstance().getMolecule(MoleculeById((*moliter)->getId()));
+    const molecule * const mol = const_cast<const World &>(World::getInstance()).
+        getMolecule(MoleculeById((*moliter)->getId()));
     if ((mol != NULL) && (mol == *moliter)) {
       addMolecule(mol);
Index: src/UIElements/Views/Qt4/MoleculeList/SpecificItems/QtMoleculeItem_atomcount.hpp
===================================================================
--- src/UIElements/Views/Qt4/MoleculeList/SpecificItems/QtMoleculeItem_atomcount.hpp	(revision 97445f1edda30c6d17472c562f9832a49df3e644)
+++ src/UIElements/Views/Qt4/MoleculeList/SpecificItems/QtMoleculeItem_atomcount.hpp	(revision 63fb7a963007e0f94b955d96ca949cd435eacb2a)
@@ -44,5 +44,6 @@
   void internal_updateState()
   {
-    const molecule * mol = World::getInstance().getMolecule(MoleculeById(molid));
+    const molecule * mol = const_cast<const World &>(World::getInstance()).
+        getMolecule(MoleculeById(molid));
     if (mol != NULL)
       setText(QString::number(mol->getAtomCount()));
Index: src/UIElements/Views/Qt4/MoleculeList/SpecificItems/QtMoleculeItem_formula.hpp
===================================================================
--- src/UIElements/Views/Qt4/MoleculeList/SpecificItems/QtMoleculeItem_formula.hpp	(revision 97445f1edda30c6d17472c562f9832a49df3e644)
+++ src/UIElements/Views/Qt4/MoleculeList/SpecificItems/QtMoleculeItem_formula.hpp	(revision 63fb7a963007e0f94b955d96ca949cd435eacb2a)
@@ -47,5 +47,6 @@
   void internal_updateState()
   {
-    const molecule * mol = World::getInstance().getMolecule(MoleculeById(molid));
+    const molecule * mol = const_cast<const World &>(World::getInstance()).
+        getMolecule(MoleculeById(molid));
     if (mol != NULL)
       setText(QString(mol->getFormula().toString().c_str()));
Index: src/UIElements/Views/Qt4/MoleculeList/SpecificItems/QtMoleculeItem_name.hpp
===================================================================
--- src/UIElements/Views/Qt4/MoleculeList/SpecificItems/QtMoleculeItem_name.hpp	(revision 97445f1edda30c6d17472c562f9832a49df3e644)
+++ src/UIElements/Views/Qt4/MoleculeList/SpecificItems/QtMoleculeItem_name.hpp	(revision 63fb7a963007e0f94b955d96ca949cd435eacb2a)
@@ -44,5 +44,6 @@
   void internal_updateState()
   {
-    const molecule * mol = World::getInstance().getMolecule(MoleculeById(molid));
+    const molecule * mol = const_cast<const World &>(World::getInstance()).
+        getMolecule(MoleculeById(molid));
     if (mol != NULL)
       setText(QString(mol->getName().c_str()));
Index: src/UIElements/Views/Qt4/Qt3D/GLMoleculeObject_molecule.cpp
===================================================================
--- src/UIElements/Views/Qt4/Qt3D/GLMoleculeObject_molecule.cpp	(revision 97445f1edda30c6d17472c562f9832a49df3e644)
+++ src/UIElements/Views/Qt4/Qt3D/GLMoleculeObject_molecule.cpp	(revision 63fb7a963007e0f94b955d96ca949cd435eacb2a)
@@ -69,5 +69,6 @@
 static QGLSceneNode *createMoleculeMesh(const moleculeId_t molid, QObject *parent)
 {
-  const molecule *molref = World::getInstance().getMolecule(MoleculeById(molid));
+  const molecule *molref = const_cast<const World &>(World::getInstance()).
+      getMolecule(MoleculeById(molid));
   if (molref == NULL) {
     ELOG(1, "Could not createMoleculeMesh, molecule with id " << molid << " already gone.");
@@ -156,5 +157,6 @@
 {
   // sign on as observer (obtain non-const instance before)
-  const molecule *_molecule = World::getInstance().getMolecule(MoleculeById(moleculeid));
+  const molecule *_molecule = const_cast<const World &>(World::getInstance()).
+      getMolecule(MoleculeById(moleculeid));
   if (_molecule != NULL) {
     _molecule->signOn(this, molecule::AtomInserted);
@@ -194,5 +196,6 @@
 {
   // sign on as observer (obtain non-const instance before)
-  const molecule *_molecule = World::getInstance().getMolecule(MoleculeById(moleculeid));
+  const molecule *_molecule = const_cast<const World &>(World::getInstance()).
+      getMolecule(MoleculeById(moleculeid));
   if (_molecule != NULL) {
     _molecule->signOn(this, molecule::AtomInserted);
@@ -225,5 +228,6 @@
 {
   if (isSignedOn) {
-    const molecule *_molecule = World::getInstance().getMolecule(MoleculeById(moleculeid));
+    const molecule *_molecule = const_cast<const World &>(World::getInstance()).
+        getMolecule(MoleculeById(moleculeid));
     if (_molecule != NULL) {
       _molecule->signOff(this, molecule::AtomInserted);
@@ -247,5 +251,6 @@
 void GLMoleculeObject_molecule::init()
 {
-  const molecule *_molecule = World::getInstance().getMolecule(MoleculeById(moleculeid));
+  const molecule * const _molecule = const_cast<const World &>(World::getInstance()).
+      getMolecule(MoleculeById(moleculeid));
   if (_molecule == NULL) {
     ELOG(1, "GLMoleculeObject_molecule cannot init, molecule with "
@@ -320,5 +325,6 @@
 void GLMoleculeObject_molecule::reinit()
 {
-  const molecule *_molecule = World::getInstance().getMolecule(MoleculeById(moleculeid));
+  const molecule * const _molecule = const_cast<const World &>(World::getInstance()).
+      getMolecule(MoleculeById(moleculeid));
   if (_molecule == NULL) {
     ELOG(1, "GLMoleculeObject_molecule cannot reinit, molecule with "
@@ -348,5 +354,6 @@
 {
   isBoundingBoxUptodate = true;
-  const molecule *_molecule = World::getInstance().getMolecule(MoleculeById(moleculeid));
+  const molecule * const _molecule = const_cast<const World &>(World::getInstance()).
+      getMolecule(MoleculeById(moleculeid));
   if (_molecule == NULL) {
     ELOG(1, "GLMoleculeObject_molecule cannot updateBoundingBox, molecule with "
@@ -375,5 +382,6 @@
 void GLMoleculeObject_molecule::recieveNotification(Observable *publisher, Notification_ptr notification)
 {
-  const molecule *_molecule = World::getInstance().getMolecule(MoleculeById(moleculeid));
+  const molecule * const _molecule = const_cast<const World &>(World::getInstance()).
+      getMolecule(MoleculeById(moleculeid));
   if (publisher == dynamic_cast<const Observable*>(_molecule)){
     // notofication from atom
Index: src/UIElements/Views/Qt4/Qt3D/GLWorldScene.cpp
===================================================================
--- src/UIElements/Views/Qt4/Qt3D/GLWorldScene.cpp	(revision 97445f1edda30c6d17472c562f9832a49df3e644)
+++ src/UIElements/Views/Qt4/Qt3D/GLWorldScene.cpp	(revision 63fb7a963007e0f94b955d96ca949cd435eacb2a)
@@ -162,5 +162,6 @@
 {
    LOG(3, "INFO: GLMoleculeObject_molecule - mol " << no << " has been clicked.");
-   const molecule *mol= World::getInstance().getMolecule(MoleculeById(no));
+   const molecule * const mol= const_cast<const World &>(World::getInstance()).
+       getMolecule(MoleculeById(no));
    ASSERT(mol, "Atom without molecule has been clicked.");
    molids_t ids(1, mol->getId());
