message: check if atom has associated residue
diff: @@ -189,7 +189,11 @@ void FlexInfo::extractFlex(OpenBabel::OBMol& receptor, OpenBabel::OBMol& rigid,
  std::unordered_map<std::size_t, double> residues_distances;
  FOR_ATOMS_OF_MOL(a, rigid){
  if(a->GetAtomicNum() == 1) continue; //heavy atoms only
  - //if(!isSideChain(a->GetResidue()->GetAtomID(&(*a)))) continue; // skip backbone
  + if (a->GetResidue() != NULL){ // Check
  + // TODO: @RMeli figure out exactly then this happens
  + if (!isSideChain(a->GetResidue()->GetAtomID(&(*a))))
  + continue; // skip backbone
  + }
  vector3 v = a->GetVector();
  if (b.ptIn(v.x(), v.y(), v.z()))
  