Implementation of the LDA+U method using the full-potential linearized augmented plane-wave basis

We provide a straightforward and efficient procedure to combine the local density approximation plus Hubbard U (LDA+U) total-energy functional with the full-potential linearized augmented plane-wave method. A detailed derivation of the LDA+U Kohn-Sham-type equations is presented for the augmented plane-wave basis set, and a simple ``second-variation''-based procedure for self-consistent LDA+U calculations is given. The method is applied to calculate the electronic structure and magnetic properties of NiO and Gd. The magnetic moments and band eigenvalues obtained are in very good quantitative agreement with previous full-potential linear muffin-tin orbital calculations. We point out that LDA+U reduces the total d charge on Ni by 0.1 in NiO.