Hi,
If :DIS at the end of the calculation is in the
range 0.006-0.2, then it's huge. Do the calculations
with "-cc 0.0001".
FT
On Thursday 2019-01-17 21:19, Victor Zenou wrote:
Date: Thu, 17 Jan 2019 21:19:31
From: Victor Zenou <za...@post.bgu.ac.il>
Reply-To: A Mailing list for WIEN2k users <wien@zeus.theochem.tuwien.ac.at>
To: A Mailing list for WIEN2k users <wien@zeus.theochem.tuwien.ac.at>
Subject: Re: [Wien] proper k-points for Nd
Dear Lauri
Thanks for your answer
I used only energy convergence criteria (10^-4). Still the charge convergence
was between 0.006 and 0.2 e.
The nearest neighbor distance is 6.856 a.u, I used RMT=2.7 a.u., summed to 5.4
which is much lower than 6.856. Usually large RMT is preferred to make the
calculations as fast as possible. I plan to check a phases in Al-Ti-Nd and I
chose RMT equal to 2.3, 2.5 and 2.7 respectively.
Victor
בתאריך יום ה׳, 17 בינו׳ 2019 ב-11:16 מאת Laurence Marks
<l-ma...@northwestern.edu>:
With such large RMT you certainly need HDLO for Nd, perhaps both d & f. I
would not want to use such large RMTs.
Have you checked that the charge convergence is good?
_____
Professor Laurence Marks
"Research is to see what everybody else has seen, and to think what nobody else has
thought", Albert Szent-Gyorgi
www.numis.northwestern.edu
On Thu, Jan 17, 2019, 03:04 Victor Zenou <za...@post.bgu.ac.il wrote:
Hi
Here is updated question:
Dear Wien2k users
I'm using wien2k version 17.1 installed on Ubunto 18.04.
I need to calculate the enthalpy of formation of few intermetallic phases that
include Nd. For that element I used RMT=2.7 a.u. and RMT*Kmax=8.5 for
spin-polarization calculations via GGA-PBE. I didn't try spin-orbit coupling.
Yet.
The first stage is to choose proper k-points, which will give accurate results
(I used 1x10^-4 Ryd for energy convergence) on one hand, but on the
other hand won't be expensive in terms of computing time.
I noticed that there are large energy fluctuations (1x10^-2 Ryd; which are 2
order of magnitude higher than the energy accuracy (defined by
convergence criterion), even when I went to 15,000 k-points. Here is a list of
energy as function of k-points:
K-points IBZ E [Ryd]
100 8 -77040.4692
500 38 -77040.4780
1000 81 -77040.5062
2000 120 -77040.5061
3000 208 -77040.4391
4000 244 -77040.4699
5000 280 -77040.4878
7500 455 -77040.4707
10000 540 -77040.4881
15000 840 -77040.4694
I would be happy to get an idea what could have gone wrong.
Best regards, Victor
בתאריך יום ד׳, 16 בינו׳ 2019 ב-13:59 מאת Victor Zenou
<za...@post.bgu.ac.il>:
Dear Wien2k users
I'm using wien2k version 17.1 installed on Ubunto 18.04.
As a part of investigation of intermetallic phases in Al-Ti-Nd system, I
need to calculate the enthalpy of formation of few phases in
that system. For that purpose, I start calculating enthalpy (equal to
energy at 0K) for each element and phase at their optimal relaxed
state. I used spin-polarization calculations. (GGA-PBE) As advised in
Wien2k website I used the same RMT for each elements: 2.3, 2.5
and 2.7 a.u. for Al, Ti and Nd, respectively. Also proper RMT*Kmax (7.5 to
Ti, 8.5 to Nd and 7.0 for the rest).
The first stage is to choose proper k-points, which give you accurate
results (I used 1x10^-4 Ryd for energy convergence) on one hand,
but also some save computing time.
The calculation for all elements and phases went OK, but Nd. From certain
k-points the energy fluctuated between 2 values (differed by
1x10^-2). Attach a list of energy as function of k-points:
K-points IBZ E [Ryd]
100 8 -77040.4692
500 38 -77040.4780
1000 81 -77040.5062
2000 120 -77040.5061
3000 208 -77040.4391
4000 244 -77040.4699
5000 280 -77040.4878
7500 455 -77040.4707
10000 540 -77040.4881
15000 840 -77040.4694
I tried to get smart and did volume optimization using 4000 k-points,
later 5000 k-points. I got strange results.
I would be happy to get an idea what could have gone wrong.
I didn't try spin-orbit coupling
Best regards, Victor
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