defining A=1 should be the same as defining celldm(1)=1.889...=1/0.529177
stefano
On 23/06/2017 08:30, Isaiah Moses wrote:
Hi Paolo,
But how does one set CELL_PARAMETERS (angstrom)?
Because I observe that the output I obtain from vc-relax is
automatically set to
CELL_PARAMETERS (alat= 8.11400000).
Does that has to do with the unit of celldm?
I must be missing something on theses units' usage.
I appreciate your usual prompt response,
Isaiah
On Fri, Jun 23, 2017 at 7:16 AM, Paolo Giannozzi
<[email protected] <mailto:[email protected]>> wrote:
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
<[email protected] <mailto:[email protected]>> 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 <[email protected]
<mailto:[email protected]>> 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
> [email protected] <mailto:[email protected]>
> http://pwscf.org/mailman/listinfo/pw_forum
<http://pwscf.org/mailman/listinfo/pw_forum>
>
>
> _______________________________________________
> Pw_forum mailing list
> [email protected] <mailto:[email protected]>
> http://pwscf.org/mailman/listinfo/pw_forum
<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
_______________________________________________
Pw_forum mailing list
[email protected] <mailto:[email protected]>
http://pwscf.org/mailman/listinfo/pw_forum
<http://pwscf.org/mailman/listinfo/pw_forum>
--
Isaiah Abu Moses
Graduate Student,
Physics Department,
University of Ibadan,
Nigeria
_______________________________________________
Pw_forum mailing list
[email protected]
http://pwscf.org/mailman/listinfo/pw_forum
_______________________________________________
Pw_forum mailing list
[email protected]
http://pwscf.org/mailman/listinfo/pw_forum
