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

We provide a straightforward and efficient procedure to combine 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 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 LMTO calculations. We point out that LDA+U reduces the total d charge on Ni by 0.1 in NiO.