Frozen local hole approximation

The frozen local hole approximation (FLHA) is an adiabatic approximation which is aimed to simplify the correlation calculations of valence and conduction bands of solids and polymers or, more generally, of the ionization potentials and electron affinities of any large system. In this work we address the question to which extent it is possible to simplify a correlation calculation on electron hole states by focusing on so-called "frozen" local hole configurations although, in reality, the electron hole is usually delocalized over the entire system.