[Pw_forum] Two problems for pseuodopotential choosing

[Axel Kohlmeyer]

On Sun, 8 May 2005 wjyin at fudan.edu.cn wrote:

YW> Dear all,

dear yin wanjian,

YW>     I have encountered problems about pseudopotential.
YW>     
YW>     One is,
YW>     I just want to use the well-know simple BHS pseuodopotential which 
YW> parameters is directly given by Bachelet,Hamann and Schluter in 1982, 
YW> rather than ones generated by all-electron calculation again. 
YW>    Could any pseudopotential generation software generate this simple 
YW> BHS psp just from the given parameters in 1982 which could also be 
YW> used by PWSCF.

the strategy for getting BHS potentials into pwscf would be to 
turn the potential parameters into a numerical potential.
please have a look at the espresso sourcecode. 
in upftools/ncpp2upf.f90 around line 100-140 you'll find evidence,
that this converter supports BHS potentials in a specific format
(the old pwscf format).
so you could either hack this converter to read the BHS parameters from
the console or create potential files conforming to this format so you 
can convert them into UPF format.

YW>     The other is,
YW>     Is there any input parameter which determins the maximum angle 
YW> momentum for used pseudopotential. For a simple example, I just want 
YW> to use l=0 pseudopotential for all valence electrons calculation.

do i understand you correctly, that you want to use a fully local 
pseudopotential? i am not aware of a flag that allows to set that,
but you could follow a similar route as outlined above. simply
copy the l=0 potential for all angular momentum, you'd want 
to include and then convert to UPF format.

best regards,
	axel.
YW>     
YW>     Your help will be greatly appreciated!
YW> 
YW> Yin Wanjian
YW> 
YW> _______________________________________________
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YW> Pw_forum at pwscf.org
YW> http://www.democritos.it/mailman/listinfo/pw_forum
YW> 
YW> 

-- 

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Dr. Axel Kohlmeyer   e-mail: axel.kohlmeyer at theochem.ruhr-uni-bochum.de
Lehrstuhl fuer Theoretische Chemie          Phone: ++49 (0)234/32-26673
Ruhr-Universitaet Bochum - NC 03/53         Fax:   ++49 (0)234/32-14045
D-44780 Bochum  http://www.theochem.ruhr-uni-bochum.de/~axel.kohlmeyer/
=======================================================================
If you make something idiot-proof, the universe creates a better idiot.