Quantum mechnanics based method is quite popular in accurately describing the reaction mechanism, the conformation of small molecule and the accurate prediction of the energetics and electro density distribution. Here in meilerlab we apply QM based methods for accurate partial charge descriptions of small drug targets and substrates. We also apply QM based approaches such as orbital description to improve the ligand docking as it facilitite the correct representation of covalent and non-covalent interactions in molecular docking. In addition we are developing a novel algorithom to integrate QM based method with Rosetta for improving the Rosetta score function by using QM based parameters.