Crystallization of electrons and holes

The original concept of Wigner for electron crystallization is extended by considering electrons in orbitals close to nuclei. It is shown that in this case electron (or hole) crystallization can take place at high densities. This is in distinction to the homogenous electron gas considered by Wigner where only at very low densities electrons are forming a lattice. We show that Yb4As3 is an example for the case studied here. Because of the special anti-Th3P4 structure the material has, the crystallization of 4f holes can be modelled well by a band Jahn-Teller effect of strongly correlated electrons.