[Wien] Querie on the -i switch for iterations_Spin Polarized Cases

[Ghosh SUDDHASATTWA]

Thank you Gerhard, 
My idea was to calculate enthalpy of formation of a typical Laves phase AB2
And for all the individual components 
I used 
Run_lapw -cc 0.0001 -ec 0.0001 -so -i 90 -p 
I thought it might work for AB2 as well. But I did not get a smooth
variation of the volume with energy. 
I also used 
Run_lapw -cc 0.0001 -ec 0.00001 -in1ef -p which work beautifully for Fe_bcc 

The idea therefore is two fold; one to get the desired accuracy and the
second that nobody should question the result !!

SG 


-----Original Message-----
From: wien-bounces at zeus.theochem.tuwien.ac.at
[mailto:wien-bounces at zeus.theochem.tuwien.ac.at] On Behalf Of Gerhard Fecher
Sent: Wednesday, October 27, 2010 12:34 PM
To: A Mailing list for WIEN2k users
Subject: Re: [Wien] Querie on the -i switch for iterations_Spin Polarized
Cases

Do you realy need the charge convergency  -cc 0.0001 for the volume
optimization ?
What for ?

For a rough estimate -ec 0.0001 may be fine, you can sharpen the convergency
criteria afterwards.
Then try for example -cc 0.001 -ec 0.00001 and  increase the k-points (copy
the clm files don't use charge extrapolation in the second step)
check if the relaxed volume is different.

Sometimes a lot of 0's don't help a lot.

Ciao
Gerhard

====================================
Dr. Gerhard H. Fecher
Institut of Inorganic and Analytical Chemistry
Johannes Gutenberg - University
55099 Mainz
________________________________________
Von: wien-bounces at zeus.theochem.tuwien.ac.at
[wien-bounces at zeus.theochem.tuwien.ac.at]" im Auftrag von "Ghosh
SUDDHASATTWA [ssghosh at igcar.gov.in]
Gesendet: Mittwoch, 27. Oktober 2010 06:45
Bis: 'A Mailing list for WIEN2k users'
Betreff: [Wien] Querie on the -i switch for iterations_Spin Polarized Cases

Dear Wien2k users,
I was trying to volume optimize (some 5 structure changes, 4 atoms per
lattice) a cubic case with the command in the optimize.job
Runsp_lapw -cc 0.0001 -ec 0.0001 -i 90 -so -p
However, in one or two cases, the SCF did not converge. What changes could
be made keeping the same accuracy of charge and energy convergence.

SUDDHASATTWA GHOSH
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