In principle the above method, based on NBO analysis of a DFT calculation followed by a xyz2mol-based workflow for assigning formal charges and bond orders, represents a method for obtaining SMILES/RDKit mol objects based on structure and overall charge. However, relying on DFT calculations makes this method very slow, limiting its use cases. Therefore we propose a much faster approach based on atomic distances and extended Hückel calculations (available through RDKit) for the ligands . We will show that this is a robust way of obtaining a SMILES representation of a TMC that can be read into an RDKit mol object. Furthermore, we can assess the quality of this representation by comparison to the fixed CSD SMILES as well as the SMILES created based on the DFT-NBO analysis for tmQMg and tmQMg-L .