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["Zhenhua Zeng" <myid520@163.com>]

Dear Matthieu,

Thank you for you reply.

I know where the problem come from now. I.e. for a slab calculation,
the frequencies of GAMMA point are the projected frequencies from gamma to L 
point in bulk,
so acoustic modes are not necessary zero at GAMMA point,
and ASR may give wrong results for slab calculation.

I know you are good at phonon and el-ph coupling,
and have the paper on the influence of s-o coupling on phonon and energy band 
of Pb.
Then several question about these:
[1] Did you calculate the phonon of Pb slab too?  If yes? Do you have the 
similar results?

[2] The abinit version i used is 5.3.4. Does it include the s-o coupling for 
phonon calculation? 

Best Wishes                      
Zhenhua Zeng

-------------------------------------------------------------
From：matthieu verstraete
sent:：2008-11-10 21:59:30
To：forum@abinit.org
Subject：Re: [abinit-forum] Inconsistent phonon frequency between out file 
andanaddb

>
>On Mon, Nov 10, 2008 at 3:41 AM, Zhenhua Zeng <myid520@163.com> wrote:
>
>> Hello Everyone,
>>
>> I'm callculating phonon of Pb(111) slab: 6 ML Pb with a vaccum about 12
>> \AA,
>> I found that
>> [1] the result printed out in the out file are not consistent with the
>> results of anaddb.
>> [2] I.e. the results in out file seem meaningless.
>>
>> For example the phonon at gamma  point:
>> out file(cm-1): 3.754035E+01  3.922919E+01  3.951580E+01  4.177673E+01 ....
>> anaddb  (cm-1): almost zero   almost zero   almost zero   about 1.0E+01
>> ....
>
>anaddb imposes the acoustic sum rule, whereas abinit (in the single q phonon
>run) does not necessarily (not by default). The ASR error is quite large in
>your case (30cm-1) and shifts the other modes quite a lot too. It's probably
>correct, though, but you should check.
>
>
>
>> [2] why anaddb can give a 'reasonable' result, even though frequencies in
>> the out file are so bad?
>
>because the ASR error is systematic, and is subtracted out everywhere by the
>ASR correction. I should write up a note about this, 1 question out of 20 is
>on the same problem.
>
>
>
>> These parameters are ok for the phonon calculation of bulk  Pb.
>
>in principle you should re-do convergence studies for the surface, but I
>suspect it should be ok. Check what the in-plane Fermi-surface is like!
>
>Matthieu
>
>-- 
>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>Dr. Matthieu Verstraete
>
>European Theoretical Spectroscopy Facility (ETSF)
>Dpto. Fisica de Materiales,
>U. del Pais Vasco,
>Centro Joxe Mari Korta, Av. de Tolosa, 72,   Phone: +34-943018393
>E-20018 Donostia-San Sebastian, Spain        Fax  : +34-943018390
>
>Mail : matthieu.jean.verstraete@gmail.com
>http://www-users.york.ac.uk/~mjv500
>
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