=?gb2312?B?u9i4tA==?=:Re: [Pw_forum] Two problems for pseuodopotential choosing

[wjyin at fudan.edu.cn]

Dear Axel,
     Thanks for your useful help.
     My second question could not be presented clearly.
   
     When sovling Kohn-Sham equation by plane-wave pseudopotential 
method , we 
deal different valence pseudowave of momentum l=0,1,2... with 
different 
non-local l-dependent pseudopotential. Thus is illustrated in 220-221, 
Part 
III, <<Electronic Structure>>(by Richard M.Martin). 

   As approximation, we are not necessary using large l 
pseudopotential.
Could I set this maximum l in PWSCF . or it could be decided in 
pseudopotential 
generation.
    
best wishes
Yin Wanjian 


----- 原邮件 -----
从: Axel Kohlmeyer <axel.kohlmeyer at theochem.ruhr-uni-bochum.de>
日期: 星期日, 五月 8日, 2005 下午5:55
主题: Re: [Pw_forum] Two problems for pseuodopotential choosing

> 
> 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 
> fromthe 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> _______________________________________________
> YW> Pw_forum mailing list
> YW> Pw_forum at pwscf.org
> YW> http://www.democritos.it/mailman/listinfo/pw_forum
> YW> 
> YW> 
> 
> -- 
> 
> 
=======================================================================
> Dr. Axel Kohlmeyer   e-mail: axel.kohlmeyer at theochem.ruhr-uni-
> bochum.deLehrstuhl fuer Theoretische Chemie          Phone: ++49 
> (0)234/32-26673
> Ruhr-Universitaet Bochum - NC 03/53         Fax:   ++49 (0)234/32-
> 14045D-44780 Bochum  http://www.theochem.ruhr-uni-
> 
bochum.de/~axel.kohlmeyer/=============================================
==========================
> If you make something idiot-proof, the universe creates a better 
> idiot.
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