Iterative scheme of the symmetry adapted perturbation theory

4 ITERATIVE SCHEME OF THE SYMMETRY ADAPTED PERTURBATION THEORY 

We now have two issues either to construct another zero-order Hamiltonian, for which the function would be an eigenfunction (then the perturbation would be small and the Rayleigh-Schrodinger perturbation theory might be applied), or to abandon any Rayleigh-Schrodinger perturbation scheme and replace it by 

Appendix Y, p. 1050. we show, how the charge distribution changes when the Pauli exclusion principle is forced by a proper projection of the wave function. 

The second possibility relies on an iterative solution of the Schrodinger equation, forcing the proper symmetry of the intermediate functions. The method was proposed mainly by Bogumil Jeziorsld and Wlodzimierz Kolos. 

Oaude Bloch was probably the first to write the Schrodinger equation in the form shown in formulae (10.76) and (10.59). Let us recall them in a notation Bloch equatior s adapted to the present situation  

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