[Pw_forum] question about pwcond.x

[Andrea Dal Corso]

On Tue, 2006-02-14 at 16:07 +0100, Gabriel Autès wrote:
> Hi,
> 
> I try to calculate the transmission of a monoatomic iron wire with
> pwcond.x (following example12 Alwire).
> But the band structure I get from pwcond.x is different from the one
> obtained with pw.x, which leads to a wrong transmission curve.
> Actually, the (dxy/dx²-y²) and the (dxz/dyz) bands are shifted of a few eV
> by the pwcond.x calculation.
> 
> Any idea why this happens?
> 
> 
> Maybe I made a mistake in my input:
> *input file for pw.x:
> ==============================================================
> &control
>     calculation='scf'
>     restart_mode='from_scratch',
>     pseudo_dir= '/home/gautes/SOFTWARE/pseudo/',
>     outdir='/home/gautes/WORK/espresso/Tmp'
>     prefix='fe_wire'
>  /
>  &system
>     ibrav = 6,
>     celldm(1) =30.0,
>     celldm(3) =0.143333333,
>     nat= 1,
>     ntyp= 1,
>     nspin= 1,
>     ecutwfc= 25.0,
>     ecutrho= 150.0
>     occupations='smearing',
>     smearing='methfessel-paxton',
>     degauss=0.01
>  /
>  &electrons
>     conv_thr = 1.0e-8
>     mixing_beta = 0.7
>  /
> ATOMIC_SPECIES
>  Fe 55.847 Fe_us_gga_d2.1.8.pseudo.UPF
> ATOMIC_POSITIONS
>  Fe 0.0 0.0 0.000
> K_POINTS (automatic)
>  1 1 100 0 0 0
> ====================================================================
> 
> 
> *input file for pwcond.x:
> ====================================================================
>  &inputcond
>     outdir='/home/gautes/WORK/espresso/Tmp/',
>     prefixl='fe_wire',
>     prefixs='fe_wire',
>     tran_file='trans.fewire',
>     ikind=1,
>     energy0=5.0d0,
>     denergy=-0.1d0,



>     ewind=1.d0,
>     epsproj=1.d-3,
>     nz1 = 1

Most probably the calculation is not converged with respect to these
three parameters. Try increasing ewind, decreasing epsproj and
increasing nz1. Typical values are ewind=3.d0, epsproj=1.d-6, nz1=5 or
10

Andrea


>  /
>     1                #number of k_perp points
>     0.0  0.0  1.0    #kx, ky ,weight
>     100
> =================================================================
> 
> thanks
> 
-- 
Andrea Dal Corso                    Tel. 0039-040-3787428
SISSA, Via Beirut 2/4               Fax. 0039-040-3787528
34014 Trieste (Italy)               e-mail: dalcorso at sissa.it