An attempt has been made to enhance the thermodynamic capabilityof the general purpose modelling and simulation environment OpenModelica. The propertydatabase ChemSep and the thermodynamic algorithms of DWSIM are made available inOpenModelica. Following three approaches, listed in the order of increasing computationaleciency, are attempted in this work: Python-C API, socket programming and a nativeport. The most ecient method of native port is adopted to make available NRTL, Peng-Robinson, UNIFAC and UNIQUAC algorithms in OpenModelica. Through several examples,OpenModelica results are compared with Aspen Plus, indicating a good match in all cases.This work is released as open source to enhance the collaboration amongst chemical engineers.