The dilatation volumes of basic defects in the O sub-system were calculated by using molecular dynamics methods. Defects in the form of O atom disordering on the basal plane, O vacancies, and interstitial atoms, were considered. It was shown that the dilatation volume of an O vacancy (position O[4]) had a positive sign and was of the order of several cubic Angstrom units. This was attributed to a change in the charge state of the nearest Cu atoms.

N.N.Degtyarenko, V.F.Elesin: Low Temperature Physics, 1996, 22[5], 447-8