Magnetic contribution to the vacancy-formation energy: An alternative method for theab initiocalculation of effective exchange parameters in ferromagnetic metals

An alternative method is suggested for the ab initio calculation of effective exchange parameters in ferromagnetic metals from the magnetic contribution to the vacancy-formation energy. The advantage of the method is that it does not require a computer code that is able to rotate magnetic moments out of parallel alignment. Based on this approach, a linear-muffin-tin-orbital calculation in the atomic-sphere approximation yields a much larger effective exchange parameter than other approaches, and a likely reason for this discrepancy is discussed.