[Pw_forum] vc-relax cell parameters are not changing

[Paolo Giannozzi]

And, by the way, it is a bad habit to set the lattice parameter to the
conversion factor between a.u. and A. One should use instead
CELL_PARAMETERS (angstrom)
to specify lattice vectors in A

Paolo

On Fri, Jun 23, 2017 at 4:55 AM, Stefano de Gironcoli <degironc at sissa.it> wrote:
> The lattice parameter does not change, it is not updated along vc-relax, the
> lattice vectors do.
> Using bfgs you don't need to define dt
>
> stefano
> (sent from my phone)
>
> On 23 Jun 2017, at 01:55, Brendan Smith <mrbsmith58 at gmail.com> wrote:
>
> Hello all,
>
> I am doing a the following vc-relax calculation and the unit cell paramters
> are not changing. I have looked at other posts which descirbes similar
> problems, but it does not remedy my problem. Below is my input.
> Best,
> Brendan
>
>
> &CONTROL
>   calculation = 'vc-relax',
>   dt = 20.67055,
>   nstep = 1000,
>   pseudo_dir = './'
>   outdir = './',
>   prefix = 'x',
>   disk_io = 'low',
> /
>
> &SYSTEM
>   ibrav = 0,
>   celldm(1) = 1.89,
>   nat = 16,
>   ntyp = 3,
>   nspin = 1,
>   nbnd = 120,
>   ecutwfc = 70,
>   ecutrho = 560,
>   tot_charge = 0.0,
>   occupations = 'smearing',
>   smearing = 'gaussian',
>   degauss = 0.005,
>   nosym = .true.,
> /
>
> &ELECTRONS
>   electron_maxstep = 1000,
>   conv_thr = 1.D-5,
>   mixing_beta = 0.45,
> /
>
> &IONS
>   ion_dynamics = 'bfgs',
>   ion_temperature = 'andersen',
>   tempw = 300.00 ,
>   nraise = 1,
> /
>
> &CELL
>   cell_dynamics = 'bfgs',
>   press_conv_thr = 0.5,
>   cell_factor = 2.0,
>   cell_dofree = 'all',
> /
>
> ATOMIC_SPECIES
>  O  15.9994  O_pbe_v1.2.uspp.F.UPF
>  V  50.9415  V_pbe_v1.uspp.F.UPF
>  Pb 207.2    Pb.pbe-dn-rrkjus_psl.0.2.2.UPF
>
> K_POINTS automatic
>  3 3 3 0 0 0
>
> CELL_PARAMETERS (alat)
>        11.5439996719         0.0000000000         0.0000000000
>         0.0000000000         3.5710000992         0.0000000000
>         0.0000000000         0.0000000000         4.3829998970
>
> ATOMIC_POSITIONS (alat)
>  V    6.940599    0.892750    0.475994
>  V    4.603400    2.678250    3.907006
>  V   10.375401    0.892750    0.475994
>  V    1.168599    2.678250    3.907006
>  O    4.974309    0.892750    4.370728
>  O    6.569691    2.678250    0.012272
>  O    0.797690    0.892750    4.370728
>  O   10.746309    2.678250    0.012272
>  O    6.978348    0.892750    2.058695
>  O    4.565652    2.678250    2.324305
>  O   10.337652    0.892750    2.058695
>  O    1.206349    2.678250    2.324305
>  O    8.658000    0.892750    0.003506
>  O    2.886000    2.678250    4.379493
>  Pb   8.500000    2.500000    1.500000
>  Pb   3.000000    1.500000    3.000000
>
>
>
>
> _______________________________________________
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum
>
>
> _______________________________________________
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum



-- 
Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche,
Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
Phone +39-0432-558216, fax +39-0432-558222