Dear all, I am working on molecule with localized d electrons and two different spin states, especially correlation due to Hund's coupling J at this moment. I tried the DFT+U+J method (PRB 84, 115108, 2011) implemented in Quantum Espresso, and found out the J dependence is quite different from the rotational invariant DFT+U (PRB 52 R5467, 1995).
I am surprised by the results, because rotational invariant DFT+U has full coulomb interaction parametrized by Slater integrals, Hund's coupling J show up in anisotropic and spin polarized interactions. As a model, it covers both Hund's first and second rule. Theoretically, I don't know what's missing in this method. Apparently, developers of DFT+U+J know how to go beyond rotational invariant DFT+U. I read the paper, but still don't understand the idea behind it. I would like to ask two questions: 1. What is not right in rotational invariant DFT+U, as a Hartree-Fock level theory regarding J? 2. How DFT+U+J improves rotational invariant DFT+U, just in general? Appreciate your help! Cheers -- Jia Chen Postdoc, Columbia University -------------- next part -------------- An HTML attachment was scrubbed... URL: http://pwscf.org/pipermail/pw_forum/attachments/20140317/eb956b17/attachment.html
