The cerium alpha-gamma phase transition is characterized by means of a many-body Jastrow-correlated wave function, which minimizes the variational energy of the first-principles scalar-relativistic Hamiltonian, and includes correlation effects in a non-perturbative way. Our variational ansatz accurately reproduces the structural properties of the two phases, and proves that even at temperature T=0K the system undergoes a first order transition, with ab initio parameters which are seamlessly connected to the ones measured by experiment at finite T. We show that the transition is related to a complex rearrangement of the electronic structure, with key role played by the p-f hybridization. The underlying mechanism unveiled by this work can hold in many Ce-bearing compounds, and more generally in other f-electron systems.
@article{arxiv.1504.04551,
title = {Electronic Origin of the Volume Collapse in Cerium},
author = {N. Devaux and M. Casula and F. Decremps and S. Sorella},
journal= {arXiv preprint arXiv:1504.04551},
year = {2015}
}