Maybe this paper also helps
K. Lejaeghere, V. Van Speybroeck G. Van Oost, and S. Cottenier
Error Estimates for Solid-State Density-Functional
Theory Predictions: An Overview by Means of the
Ground-State Elemental Crystals
Critical Reviews in Solid State and Materials Sciences, 39:1–24, 2014
DOI: 10.1080/10408436.2013.772503
Ciao
Gerhard
DEEP THOUGHT in D. Adams; Hitchhikers Guide to the Galaxy:
I think the problem, to be quite honest with you,
is that you have never actually known what the question is.
Dr. Gerhard H. Fecher
Institut of Inorganic and Analytical Chemistry
Johannes Gutenberg - University
55099 Mainz
and
Max Planck Institute for Chemical Physics of Solids
01187 Dresden
Von: wien-boun...@zeus.theochem.tuwien.ac.at
[wien-boun...@zeus.theochem.tuwien.ac.at] im Auftrag von
t...@theochem.tuwien.ac.at [t...@theochem.tuwien.ac.at]
Gesendet: Donnerstag, 1. Januar 2015 21:36
An: A Mailing list for WIEN2k users
Betreff: Re: [Wien] Convergence problem
From the total energies it's difficult to say. It's better to
compare the cohesive energies. My cohesive energies for Fe and Ni
with the WC functional are 5.54 and 5.38 eV/atom, respectively, with
an error bar of 0.05 eV/atom maximum. In this paper you can find
PBE cohesive energies calculated with the VASP code (my PBE values
agree very well with them):
http://journals.aps.org/prb/abstract/10.1103/PhysRevB.87.214102
You have to know which error is acceptable for your purposes.
On Thu, 1 Jan 2015, Muhammad Sajjad wrote:
Dear Tran Thank you for your further help. I am also attaching here with the
structure file. Please let know the E0 values you calculated for Ni and Fe.
With me
these values are -3040.43215615 and -2544.39535597 (in Ry) respectively.
On Tue, Dec 30, 2014 at 4:52 AM, t...@theochem.tuwien.ac.at wrote:
Hi,
The struct file that I used is attached. For my purpose, the size of
the unit cell was large enough to avoid spurious interactions between
neighbouring cells. Note that a, b and c are different in order to avoid
to high symmetry.
F. Tran
On Mon, 29 Dec 2014, Muhammad Sajjad wrote:
Dear Prof. Marks and F. TranThank you so much for your helpful
suggestions. I was already doing the spin polarization calculations. I
have got the convergence
by using
mixing factor 0.1, starting calculation with PRATT and then
switched to MSR1 after 7 cycles, and the command runsp_lapw -cc 0.1
-in1ef -i 150
The obtained magnetic moment was 2.9.
Dear Tran I would really appreciate if you share some more
details about case.struct file. It will definitely be helpful for me as well
as for others.
Kind Regards
Dr. Sajjad
On Mon, Dec 29, 2014 at 3:50 AM, t...@theochem.tuwien.ac.at
wrote:
The calculation for an isolated atom with a code which uses
periodic
boundary conditions (like WIEN2k) is not trivial. This is
what I have done
recently for most atoms of the periodic table (excluding
f-systems), and
for some of the transition-metal atoms this was extremely
difficult to
achieve convergence.
A few hints (that I used):
1) It is important (and necessary depending on the atom) to
reduce the
symmetry from cubic to, e.g., orthorhombic to be able to
access the
electronic configuration with the lowest energy (this is
the procedure
followed by several research groups like VASP for instance).
If necessary I can give more details about the case.struct
that I used.
2) lapw0 requires a lot of memory, while lapw1 requires both
memory and time. To reduce computer time for lapw1, I was
using
iterative digonalization (this was my command for all
atoms):
runsp_lapw -ec 0.0001 -cc 0.0001 -it -i 1000 -NI
3) For the Ni atom the magnetic moment should be 2:
:MMTOT: SPIN MAGNETIC MOMENT IN CELL =2.00238
4) I was using the default setting for mixer.
F. Tran
On Sun, 28 Dec 2014, Laurence Marks wrote:
Also, only 1 k-point (Gamma), an RMT and RKMax
similar to what you use for
bulk Ni, particularly as I assume you are doing the
calculation to get an
enthalpy of formation. You may have to use the mpi
versions as it is
probably too large for a non-mpi run.
If you are doing WC+U (or -ineece) the U (or on-site
hybrid) removes the
