First-principles calculation of impurity-solution energies in Cu and Ni

We present ab initio calculations for the solution energies of 3d impurities in Cu and Ni hosts. The calculations are based on density-functional theory and the KKR Green’s-function method. We apply a grand-canonical energy functional which is extremal against non-particle-conserving charge variations and give an extension of Lloyd’s formula for complex energies. The full nonsphericity of the charge density is used in the double counting terms. Test calculations show that it is sufficient to take the perturbation of one shell of host atoms around the impurity into account. The calculated solution energies of 3d impurities in Cu and Ni are in good agreement with the experimental data and with the values predicted by Miedema’s model.