Changes in the potential energy of atoms that constituted the nearest neighbourhood of vacancies formed in the bulk of d transition and precious cubic metals were determined. These changes agreed with available first-principles calculations of changes in the potential energy of atoms in the nearest neighbourhood of vacancies. In the cores of crystallite-conjugation regions of body-centred cubic polycrystalline d transition metals, the formation of vacancies was accompanied by positive changes in the potential energy of atoms of their nearest neighbourhood. The absolute magnitudes of these changes were several times less than the changes in the potential energy of atoms of the nearest neighbourhood of vacancies in the bulk, in accord with the relationship between the enthalpies of formation of vacancies in these regions of polycrystals. The changes in the potential energy of atoms of the nearest neighbourhood of vacancies formed in the cores of crystallite-conjugation regions of face-centred cubic polycrystalline metals were negative because of the split structure of vacancies in the crystallite-conjugation regions cores of such metals.Changes in the Potential Energy upon the Formation of Vacancies in the Volume and in the Cores of Crystallite-Conjugation Regions in Cubic Polycrystalline Metals. S.M.Klotsman, A.N.Timofeev, M.S.Dudarev: Physics of Metals and Metallography, 2007, 103[5], 481-8