Optimization and transferability of non-electrostatic repulsion in the polarizable density embedding model

5 years ago

Optimization and transferability of non-electrostatic repulsion in the polarizable density embedding model

Dalibor Hršak, Jógvan Magnus Haugaard Olsen, Jacob Kongsted

Embedding techniques in combination with response theory represent a successful approach to calculate molecular properties and excited states in large molecular systems such as solutions and proteins. Recently, the polarizable embedding model has been extended by introducing explicit electronic densities of the molecules in the nearest environment, resulting in the polarizable density embedding (PDE) model. This improvement provides a better description of the intermolecular interactions at short distances. However, the electronic densities of the environment molecules are calculated in isolation, which results in overestimation of the non-electrostatic repulsion, thereby requiring a scaling of this term. In this work, an optimal scaling factor for the non-electrostatic repulsion term is examined by comparing intermolecular interaction energies obtained with embedding techniques to reference interaction energies calculated on the basis of full quantum-mechanical calculations. The obtained optimal factors are used in PDE calculations of various ground- and excited-state properties of molecules embedded in solvents described as polarizable environments. © 2017 Wiley Periodicals, Inc. In this study, we have optimized the scaling factor for the non-electrostatic repulsion in the polarizable density embedding (PDE) model. The nonscaled repulsion term is overestimated because the electron densities of the environment molecules are calculated for isolated fragments. The optimization was performed through PDE calculations of the interaction energy curves of four dimer complexes and they were compared to the reference results based on full QM description of the dimers. The PDE model with optimized factors has thereafter been applied to calculation of various molecular response properties.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/jcc.24859