Core Level Shifts / XPS -- experience with quaility of results?
Posted: Mon Dec 01, 2008 6:36 pm
Dear VASP users,
I am doing some CLS estimates for an TM-oxide system and am trying to determine the best way to get "accurate qualitative" results. I increased the plane wave cutoffs, EDIFFG, and precision to accurate, but use the (converged) k-point mesh from the preceding structure optimization. I presently use the "accurate final state" approximation (ICORLEVEL=2).
I got a few results that are sensible in comparison to experimental data, although the shifts are sometimes overestimated by a factor of 2 (or ~1.5eV).
Does someone have experience with such calculations? Which kind of error bars do I have to expect, given that this is based on pseudopotentials, and which approximation is the best for comparison to XPS data?
Also I have this recent posting warning that core eigenstate energy calculations are not officially supported: http://cms.mpi.univie.ac.at/vasp-forum/ ... php?4.4927
What is the problem with that, and how can I test whether the calculation I am doing are not plagued by this problem?
Thanks,
Jan
(My old post: http://cms.mpi.univie.ac.at/vasp-forum/ ... php?4.3153)
I am doing some CLS estimates for an TM-oxide system and am trying to determine the best way to get "accurate qualitative" results. I increased the plane wave cutoffs, EDIFFG, and precision to accurate, but use the (converged) k-point mesh from the preceding structure optimization. I presently use the "accurate final state" approximation (ICORLEVEL=2).
I got a few results that are sensible in comparison to experimental data, although the shifts are sometimes overestimated by a factor of 2 (or ~1.5eV).
Does someone have experience with such calculations? Which kind of error bars do I have to expect, given that this is based on pseudopotentials, and which approximation is the best for comparison to XPS data?
Also I have this recent posting warning that core eigenstate energy calculations are not officially supported: http://cms.mpi.univie.ac.at/vasp-forum/ ... php?4.4927
What is the problem with that, and how can I test whether the calculation I am doing are not plagued by this problem?
Thanks,
Jan
(My old post: http://cms.mpi.univie.ac.at/vasp-forum/ ... php?4.3153)