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[Philippe Ghosez <Philippe.Ghosez@ulg.ac.be>]

Dear Hongkien,

you should probably specify the number of bands explicitely
in the input (it seems it is not in your file) .

If you treat semicore states, I think it should be  nband = 20
(40 valence electrons: 10 electrons from Ba 5s,5p,6s
+ 12 electrons from Ti 3s,3p,3d,4s + 3x6 electrons from O 2s,2p)

Cheers,

Philippe.


On 30 Aug 2007, at 21:03, hongkien wrote:

> Dear abinit users,
>
>     I have been calculating the ferroelctric properties of BaTiO3 using
> the finite electric field method.For zero field, the code could give 
> the
> polarization of berry phase. unfortunately, the code produced the error
> as the electric field was turned on:
>
> initberry: ERROR -
>   In a finite electric field calculation, nband must be equal
>   to the number of valence bands.
>
>  leave_new : decision taken to exit ...
>
> The nband was given varing from 22 to 13, but still could not give the
> right number of valence bands. From the experience in using PWSCF, the
> number of valence bands should be half of total valence electrons in 
> the
> cell, then it should be 22. And as we know, BaTiO3 was a classic
> insulator avoiding the metal collpase in berry phase calculation.I am
> frustrated by this problem, any suggestion will be highly
> appreciated.Thank you in advance.
>
> My input file was pasted here:
> # Finite electric field calculation of alas at clamped atomic positions
> # (M. Veithen, 04.5.2005)
>
> #Definition de la maille elementaire
> #**********************************
>    acell 3*7.6153
>    rprim
> 1     0     0
> 0      1      0
> 0     0      1.01319
>
> #Definition des atomes
> #*********************
>    natom 5
>    ntypat 3
>    znucl 56  22  8
>    typat 1 2 3  3  3
>    xred
> 0.00000     0.00000     0.00000
> 0.50000   0.50000   0.50000
> 0.50000   0.50000   0.00000
> 0.00000     0.50000   0.50000
> 0.50000   0.00000     0.50000
> #Definition de la procedure scf
> #******************************
>    iscf 5
>    nstep 15
>
> #Definition de la base d'ondes planes
> #************************************
>    ecut  20
>    ecutsm 0.5
>    kptopt 1
>    ngkpt 6 6 6
>    nshiftk 1
>    shiftk 0.5 0.5 0.5
>
>    toldfe 1.0d-12
>
>
> ndtset  11
>  # ndtset   2
> jdtset  11
>  21 22 23  24  25     # The additional 8 values of the field have been
> suppressed to spare CPU time
>      31   32  33  34  35
>
> berryopt11 -1       rfdir11    0  0  1
>
> berryopt21  4       efield21   0.000  0.000  0.001    getwfk21  11
> berryopt22  4       efield22   0.000  0.000  0.002    getwfk22  21
> berryopt23  4       efield23   0.000  0.000  0.003    getwfk23  22
> berryopt24  4       efield24   0.000  0.000  0.004    getwfk24  23
> berryopt25  4       efield25   0.000  0.000  0.005    getwfk25  24
>
> berryopt31  4       efield31  -0.000 -0.000 -0.001    getwfk31  11
> berryopt32  4       efield32  -0.000 -0.000 -0.002    getwfk32  31
> berryopt33  4       efield33  -0.000 -0.000 -0.003    getwfk33  32
> berryopt34  4       efield34  -0.000 -0.000 -0.004    getwfk34  33
> berryopt35  4       efield35  -0.000 -0.000 -0.005    getwfk35  34
>
>
> nbdbuf 0
>
>
>
>  Best regards,
>
> Hongkien Feng
>
> Physics department
> Beijing University of
> aeronautics&astronautics
--------------------------------------------------
Philippe GHOSEZ
Universite de Liege
Institut de Physique, Bat. B5
Allee du 6 aout, 17
B- 4000 Sart Tilman
BELGIUM

Phone : ++(32) (0)4-366.36.11
Fax   : ++(32) (0)4-366.36.29
E-mail: Philippe.Ghosez@ulg.ac.be

http://www.ulg.ac.be/phythema
--------------------------------------------------