Dear Wien2k experts, I use Wien2k 13.1. I am trying some basic LSDA/GGA (not +U) calculations for (111)-layered AFM NiO with the setup as suggested in the exercises below:
http://www.wien2k.at/events/ws2008/talks/Exercises_08.pdf However, I find that although it reaches an AFM solution, the local magnetic moment at fixed volume is much too small compared to previous LSDA/GGA calculations (e.g. Tran, Blaha, et al, Phys. Rev. B 74:155108). In addition, relaxing the volume I find it to collapse to a much too small volume and consequently a very small magnetic moment. More specifically: With plain PBE-GGA I get the local spin moment 1.1 bohr magnetons as compared to 1.4. This is at the GGA (cubic) lattice constant 4.2 Å corresponding to the hexagonal lattice constants a=5.61220 and c=27.49406 a.u.. With LSDA I get 0.9. I've tried increase the number of k-points, rkmax etc, but this doesn't seem to be the problem. Relaxing the volume with LSDA I get a=5.15171 and c=25.23811 a.u. corresponding to a=3.86 Å, and with the magnetic moment 0.6 bohr magnetons. In the reference above you got 4.07 Å and 1.2 bohr magnetons. I use the attached struct file and initalize calculations with init -b -sp -vxc 5 -numk 10000 -rkmax 9.0 -ecut -9.0 having switched up/down for Ni1 and Ni2 in the inst file, and I make O nonmagnetic. I start it with runsp_lapw and I get no warnings or convergence problems down to 1 microRy. So I believe there must be something wrong with my struct file. Could you please check if you see anything weird? Best regards, Marcus Ekholm Linköping University Sweden
NiO.struct
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