An open source COSMO-RS implementation and parameterization supporting the efficient implementation of multiple segment descriptors

The model COSMO-RS (Conductor-like screening model for realistic solvation) is based on the approximation of molecular interactions by the interactions of surface segments from the molecular cavities. These segment interactions are functions of the segment properties i.e. descriptors, with the most important descriptor being the screening charge density. Whereas the inclusion of further descriptors can lead to improved accuracy for the models predictions, it also increases the computational demand due to the growth of the central nonlinear equation system of COSMO-RS. In this work, we present an algorithm that efficiently allows the introduction of further segment descriptors at moderate size increase of the central equation system. It is included into our implementation of COSMO-RS, which is provided as open source code and will be named openCOSMO-RS in the future. Different parameterizations of the model are performed, implementing an RDKit/ORCA based workflow for the required quantum chemical calculations. In this way, the implementation is open for evaluation and refinement for a large range of academic users.