[Wien] [Wien2k User Group] Volume optimization of Zirconium

[Ghosh SUDDHASATTWA]

Dear Micheal,
 As suggested, I did the volume optimization with -5% to +5% 
The values are as shown for alpha-zirconium. 
V0 B(GPa) BP EO 
309.5778 100.0000 5.000 -14396.842
Vol 	energy 	de(Birch-Murnaghan) Pressure 
314.2133 -14396.851	0.009235	-1.432
314.2133 -14396.848	0.005909 -1.432
............................................................................
;
Are these values possible. 
I am really amazed to see the value of pressure which is negative!!!!
The ground state energy is I guess -14396.842. Am I correct? 
With spin orbit coupling, the ENE value was -14396.892 which are pretty
close.

Then why these pressure values are negative. 
I seek one more clarification. 
In the energy plot curve option, there comes "by using "*". Scf files. 
If we want to select a few files and not all the files for plotting, then do
we have to enter the file names with commas separating them? 
I ask this question because the points from the previous volume optimization
also are coming in the current plot. 

Thanks 
Suddhasattwa Ghosh 


-----Original Message-----
From: wien-bounces at zeus.theochem.tuwien.ac.at
[mailto:wien-bounces at zeus.theochem.tuwien.ac.at] On Behalf Of Michael
Fischer
Sent: Sunday, January 10, 2010 3:44 AM
To: wien at zeus.theochem.tuwien.ac.at
Subject: Re: [Wien] [Wien2k User Group] Volume optimization of Zirconium

Hello,

I can only guess on this problem, but I am quite sure that changes of 
the c/a ratio from -25% to +25% are much too large, since this probably 
leads to an overlap of the RMT spheres.
Try a set of calculations for smaller changes of the c/a ratio, e.g. 
from -5% to +5%, and make sure beforehand that the RMT spheres do not 
overlap in the most strongly distorted structures.

Regards
Michael

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