[Pw_forum] complex band of Cu(111)

[Alexander]

Dear Manoj
On my PC with espresso-4.0 I do get one band around the Fermi energy
as it should be. My output for energies around Ef looks like this:
------------------------------
        k(    1) = (  -1.0000000   1.7320000), wk =   1.0000000

 ngper, shell number =           39          24
 ngper, n2d =           39          39
 Nchannels of the left tip =            1
        k1(2pi/a)    k2(2pi/a)       E-Ef (eV)

   0.0891385   0.0000000   0.4000000
 Nchannels of the left tip =            1
        k1(2pi/a)    k2(2pi/a)       E-Ef (eV)

   0.0568822   0.0000000   0.2000000
 Nchannels of the left tip =            1
        k1(2pi/a)    k2(2pi/a)       E-Ef (eV)

   0.0228076   0.0000000   0.0000000
 Nchannels of the left tip =            1
        k1(2pi/a)    k2(2pi/a)       E-Ef (eV)

  -0.0133793   0.0000000  -0.2000000
 Nchannels of the left tip =            1
        k1(2pi/a)    k2(2pi/a)       E-Ef (eV)

  -0.0520218   0.0000000  -0.4000000
------------------------------------------------------
The problem is however that though the code calculates
correctly all the complex bands, the subroutine (summary_band.f90)
writing the bands in the file 'bands.cu' and in the common
output file confuses two branches at k_z and -k_z in the present
case where no mirror symmetry in the XY plane is present so that k_z
is not equivalent to -k_z. I will fix this problem in the CVS version
as soon as possible. Thank you for reporting the problem.
Best regards,
Alexander Smogunov

On Monday 23 June 2008 22:19, Manoj Srivastava wrote:
> Dear PWSCF users,
>  I am a new user of PWSCF and I have encountered a problem in calculating
> complex band of Cu(111). I see a band gap and there are no bands crossing
> Fermi energy. which is obviously wrong :(
> I have used hexagonal unit cells containing 3 atoms. Cu.pz-d-rrkjus.UPF
> pseudo potential was used in the calculation. It would be great if
> somebody can suggest me something.
> Following is the input file I used -
>
>  &system
>     ibrav =4,
>     celldm(1) =4.78076379, celldm(3)=2.44948974,
>     nat= 3,
>     ntyp= 1,
>     nelec=33.0,
>     nbnd=24,
>     ecutwfc =25.0,
>     occupations= 'smearing',
>     smearing='gaussian',
>     degauss=0.02
>
>  /
>  &electrons
>     diagonalization='$diago'
>     conv_thr = 1.0e-8
>     mixing_beta=0.7
>  /
>  ATOMIC_SPECIES
>  Cu       63.55  Cu.pz-d-rrkjus.UPF
>  ATOMIC_POSITIONS {bohr}
>   Cu  0.0          0.0          0.0
>   Cu  2.390381895  1.380087631  3.903477289
>   Cu  4.780763790  2.760175261  7.806954578
> K_POINTS (automatic)
> 8 8 8  0 0 0
> EOF
> # complex bands of cu(111) along the 001 direction K_perp=0
> cat > cu.cond.in << EOF
>  &inputcond
>     outdir='$TMP_DIR/'
>     prefixl='cu'
>     band_file ='bands.cu'
>     ikind=0
>     energy0=10.d0
>     denergy=-0.2d0
>     ewind=3.d0
>     epsproj=1.d-7
>  /
>     1
>    -1.0 1.732 -0.8165
>     100
> EOF
>
>
> Regards,
> Manoj
>
> _______________________________________________
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum