Orbital potentials

by **Algerien1970** Fri 29 May - 18:23

From the userguide :

In WIEN2k it is possible to go beyond standard LDA (GGA) and include orbital dependent potentials in methods like LDA+U or the ''Orbital-Polarization'', which are very usefull for strongly correlated systems.

To use these features you need to create input-files for LAPWDM and ORB (case.indm, case.inorb). You may copy a template from SRC_templates, but must modify it according to your needs. In particular you must select for which atoms and which orbitals (usually d-Orbitals of late transition metal atoms or f-orbitals for 4f/5f atoms) you want to add such a potential and also choose the proper U and J values for them. Once this is done, you can include this using the -orb switch. The density matrix (case.dmatup/dn) will be calculated after lapw2 in lapwdm, it will be mixed in mixer (consistently with the ``regular'' charge density) and the orbital dependend potentials will be calculated on orb (after lapw0). Note, you must run spin-polarized in order to use orbital potentials.

runsp_lapw -orb [-so]

If you want to force a non-magnetic solution you can constrain the spin-polarization to zero using runsp_c_lapw.
Without SO, case.vorbup/dn will be considered in LAPW1(c). With SO, it will be applied in LAPWSO (and allows coupling of nondiagonal spin-terms).