The lattice statics method was used to calculate the relaxations due to vacancy created in a lattice. The measured phonon dispersion relations and the elastic constants were used as constraints to calculate the dynamic matrix, considering interactions up to eighth neighbor. The calculation showed that the first three shells of atoms relaxed towards the vacancy. The divacancy binding energy was found to be 0.477eV, which agreed well with simpler model calculations.

Calculations on Relaxations Due to a Vacancy, Binding Energy of a Vacancy-Vacancy Pair, and Formation Energy of a Vacancy in Thorium. A.Ghorai, S.K.Sen: Physica Status Solidi B, 1987, 139[1], 77-83