[Pw_forum] Prolems with tetrahedra method

[Eyvaz Isaev]

Well, you are wrong. k-points generated by kvecs_FS.x can not be used for scf 
calculation. They are designed for nscf calculations (to map the Fermi surface), 
given in units of 2\pi/a and are Cartesian. 


Bests,
Eyvaz.




________________________________
From: yumin qian <yuminqian at gmail.com>
To: PWSCF Forum <pw_forum at pwscf.org>
Sent: Mon, April 18, 2011 3:12:26 PM
Subject: Re: [Pw_forum] Prolems with tetrahedra method


Dear Eyvaz Isaev
 
This is the input file.
 
 &control
    calculation='scf'
    restart_mode='from_scratch',
    pseudo_dir = '/home1/ymqian/soft/pwscf/psudo',
    outdir='./scfx'
    prefix='NaR',
    tstress = .true.
 /
 &system
    ibrav = 7, celldm(1) =7.767722331091487, celldm(3)=3.564658800632527,
    nat= 7, ntyp= 4, nbnd=60
    ecutwfc = 45.0, ecutrho = 400.0
    occupations='tetrahedra',
    nspin=1,
 /
 &electrons
    diagonalization='david'
    conv_thr = 1.0e-7
    mixing_beta = 0.7
 /
ATOMIC_SPECIES
Na  22.98977  Na.pbe-sp-van_ak.UPF
Fe  55.845    Fe.pbe-sp-van.UPF
Se  78.96     Se.pbe-van.UPF
O   15.9994   O.pbe-van_ak.UPF
ATOMIC_POSITIONS {crystal}
Na  0.500   0.500   0.1636801516544324
Na  0.000   0.000   0.3363198483455676
Fe  0.500   0.000   0.0000000000000000
Fe  0.000   0.500   0.0000000000000000
Se  0.000   0.000   0.1090917831789682
Se  0.500   0.500   0.3909082168210318
O   0.500   0.500   0.0000000000000000
K_POINTS {crystal}
        729
    0.000000    0.000000    0.000000  1.00
    0.000000    0.000000    0.125000  1.00
    0.000000    0.000000    0.250000  1.00
    0.000000    0.000000    0.375000  1.00
    0.000000    0.000000    0.500000  1.00
    0.000000    0.000000    0.625000  1.00
    0.000000    0.000000    0.750000  1.00
    0.000000    0.000000    0.875000  1.00
    0.000000    0.000000    1.000000  1.00 
   ..............................

2011/4/18 Eyvaz Isaev <eyvaz_isaev at yahoo.com>


>From: yumin qian <yuminqian at gmail.com>
>
>  
>>what I mean is when I use the kvec_FS.x to generate the k-points and add the 
>>k-points to the the >input file for the nscf calculation 
>
> >I run the pw.x  the output give   
> 
>>     fro/m tetrahedra : error #         1 
>
>>     cannot remap grid on k-point list 
>
> 
>Please submit your input file.
>
>
>>For example, to calculate electron-phonon coupling coefficient, for isolated 
>>systems, etc., etc., 
>>
>
>
>>There are so many case that you can't use tetrahedra method, or can you tell me 
>>for which case >that the tetrehedra method can be used safely?.
> 
>For total DOS calculations.
>
>Bests,
>Eyvaz.
>
>
> 
>2011/4/18 Eyvaz Isaev <eyvaz_isaev at yahoo.com>
>
>Hi,
>>
>> 
>>
>>
________________________________
 From: yumin qian <yuminqian at gmail.com>
>>  
>>1>I can not calculated projected density of state (PDOS) with projwfc.x .
>>
>>>     from projwfc : error #       239
>>>    reading inputpp namelist
>>
>>Something is wrong in your inputpp file. Please check it carefully. In PDOS 
>>calculations tetrahedra is not implemented/allowed.
>>
>>
>>2>    When I use the kvecs_FS.x to generate the k-points for the nscf 
>>calculation, the output return :
>>         
>>>     from tetrahedra : error #         1
>>>     cannot remap grid on k-point list 
>>
>>I can not understand this, because kvecs_FS is not related  with any program, in 
>>particular,  to tetrahedra, who complains.
>>
>>
>>>I find that not all of the generated k-points are within the first Brillouin 
>>>zone,  is there any one tell >me what is the problem?
>>  
>>These k-vectors are distributed over the full BZ, not  only in the first BZ.
>>
>>
>>>another quesiton, I think that tetrahedra method can not be used in every case 
>>>in PWSCF, except >for the force calculation that tetrahedra method may cause 
>>>prolems, who can tell me, where we >can not use tetrahedra method
>> 
>>For example, to calculate electron-phonon coupling coefficient, for isolated 
>>systems, etc., etc., 
>>
>>
>>Bests,
>>Eyvaz.
>>
>>-------------------------------------------------------------------
>>Prof. Eyvaz Isaev, 
>>Department of Physics, Chemistry, and Biology (IFM), Linkoping University, 
>>Sweden 
>>
>>Theoretical Physics Department, Moscow State Institute of Steel & Alloys, 
>>Russia, 
>>
>>isaev at ifm.liu.se, eyvaz_isaev at yahoo.com 
>>
>> 
>> 
>>_______________________________________________
>>Pw_forum mailing list
>>Pw_forum at pwscf.org
>>http://www.democritos.it/mailman/listinfo/pw_forum
>>
>>
>
>
>-- 
>
>Best Regards 
>Sincerely Y. M. Qian (钱玉敏)
>Laboratory of Condensed Matter Theory and Materials Computation 
>Institute of Physics(IOP), Chinese Academy of Sciences(CAS)
>Tel:        + 8610 8264 9827
>E-Mail:    yuminqian at gmail.com 
>P.O.Box 603   Beijing 100190
>China 
>
>_______________________________________________
>Pw_forum mailing list
>Pw_forum at pwscf.org
>http://www.democritos.it/mailman/listinfo/pw_forum
>
>


-- 

Best Regards 
Sincerely Y. M. Qian (钱玉敏)
Laboratory of Condensed Matter Theory and Materials Computation 
Institute of Physics(IOP), Chinese Academy of Sciences(CAS)
Tel:        + 8610 8264 9827
E-Mail:    yuminqian at gmail.com 
P.O.Box 603   Beijing 100190
China 
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