Abstract
Understanding of interactions between molecules and surfaces are important in researching of many different processes. Vivid examples of areas requiring knowledge of the nature of the above interactions are the catalysis and the process of ice formation.
The fundamental understanding of the activity in heterogeneous catalysis has long been the major subject in chemistry. Adsorption energy is related to catalytic activity.
According to the Sabatier principle, there is an optimum window in adsorption energies for which catalytic activity is maximum. Key descriptors in ice formation process are the nature of the active sites for molecule activation and the adsorption strength of atoms to the surface.
Thus, the existing lack of precise adsorption energies for many materials, as well as established methods of obtaining them, is a serious obstacle to further progress in those areas. Along with the experimental study of absorption phenomena, an imprescriptible approach is the construction of computer models which are used to calculate the adsorption energies and other key parameters.
Our aim is using recently developed theoretical methods such as random phase approximation (RPA) to develop efficient techniques for calculating adsorption energies. Also we use couple-cluster method (CC) which provides possibility to obtain reference quality data.
Combination of two different methods - RPA, implying periodic structure and finite cluster will allow to clarify the avenues for leveling disadvantages of two distinct approaches. The adsorption energy is implied to be equal to the sum of energy of the periodic structure, calculated by RPA and difference between energies of finite cluster, obtained with two above methods.
For this we will use specialized software actually VASP and Molpro packages. We present our initial results for water adsorption on MgO.