Non-empirical atomic potentials for ground state calculations of polymers

Abstract

Our preliminary test calculations show the ability of a very simple effective Hamiltonian to produce ab-initio quality results for calculations on polyethylene T. Similar simple models could be determined for other polymers. The most important point is that the general methodology presented in this paper is able to provide many possibilities for constructing other one and two-electron effective Hamiltonians for accurate band structure calculations of polymers. In contrast with the semi-empirical methods, these methods will have a well defined theoretical status and their range of applicability will be clearly recognized. The simple model presented in this paper can be considered as the prototype of these methods.