Evaluation of partial atomic charge calculation methods in terms of electrostatic potential calculation and optimum parameters of electronegativity equalization method (EEM)for partial atomic charge calculation

The Electrostatic Potential is of great importance in chemical reactivity since it is closely related to many of molecular properties. Despite the fact that there are significant improvements in the quantum mechanical calculation methods associated with computer technology, the atom centered partial charge approximation keeps hold of its importance in the field of estimating electrostatic potential as an inexpensive alternative to the ab initio method. However, even today, there is no universally accepted the best method for computing partial atomic charge. Here, we compare the calculation methods of atomic point charge in the view of estimating electrostatic potential and investigated on Electronegativity Equalization Method (EEM) that is computationally less expensive. In the first part of this thesis, we compared partial atomic charge calculation methods in view of predicting electrostatic potential that related to atomic charge directly. To this end, the large Grimme set included 453 molecules is used. In second part, optimum EEM parameters derived Sanderson equation and developed by Mortier was obtained using ab initio ESP as a reference value.