[Pw_forum] problem with the geometry optimization of cp.x

[Alex]

Thank you for answers

I think the problem was resolved after increasing the size of the cell in 2 borh, so I understand the possible cause of the problem: somehow the molecules were interacting with its own image (that makes sense?),when I used a non-free program (HyperChem :::: he performed a pre-optimization with periodic boundary conditions) this problem has not happened. Now, the question is to maintain a more realistic density. However, I'm relieved

Best regards
Muito obrigado a todos.



Alex W. F.  Borges
Theoretical chemistry student
Goiânia - Brazil




Em Quinta-feira, 28 de Novembro de 2013 14:16, Paolo Giannozzi <paolo.giannozzi at uniud.it> escreveu:
 
Just in case: try with other pseudopotentials. I haven't 
>heard any complaints about HGH pseudopotentials, but I 
>cannot rule out problems in the conversion to UPF format.
>have you tried simple systems first?
>
>Paolo
>
>
>On Thu, 2013-11-28 at 05:43 -0800, Alex wrote:
>> Dear user QE.
>> 
>> 
>> I'm using cp.x to perform molecular dynamics of one of bulk water
>> molecules with asparagine.
>> Following protocol, I minimized the function of wave electronics with
>> stationary nuclei.
>> 
>> 
>> However, in the second stage, during the optimization of the geometry
>> (with damp for electrons and ions) 
>> the water molecules take a non-real geometry, in which one side of the
>> molecule, the OH distance becomes 1.98 angstrorn (A).
>> The opposite side, has the normal size of the bond which is 0.97 A. I
>> confess that since I started using it very often, 
>> and sometimes does not, but do not know why that. Sometimes change is
>> functional and that resolved, sometimes not.
>> 
>> 
>> 
>> 
>> 
>> 
>> Incoherent bond distances of water after geometry optmization  >>>>>
>> H------------------O -----------H
>> (sorry by bad graphic)
>>                                    | 1.98 A|       |0.97 A|
>> 
>> 
>> 
>> 
>> Can someone help me? 
>> Put my input to be analyzed.
>> 
>> 
>> 
>> 
>> &CONTROL
>>   title = 'Asp0s'
>>   calculation = 'cp',
>>   restart_mode = 'restart',
>>   ndr = 51      !already minimized wf with sd for electrons and
>> ions=none.
>>   ndw = 52, 
>>   nstep  = 50000,
>>   iprint = 1, 
>>   isave  = 10,
>>   tstress = .TRUE.,
>>   tprnfor = .TRUE.,
>>   dt    = 5.0d0,
>>   etot_conv_thr = 1.d-8,
>>   ekin_conv_thr = 1.d-4,
>>   forc_conv_thr = 1.d-4,
>>   prefix = 'asp'
>>   pseudo_dir = 'pseudo/'
>>   outdir = './'
>> /
>> 
>> 
>> &SYSTEM
>>   ibrav = 1, 
>>   celldm(1) = 20, 
>>   celldm(2) = 0.0, 
>>   celldm(3) = 0.0, 
>>   celldm(4) = 0.0, 
>>   celldm(5) = 0.0, 
>>   celldm(6) = 0.0, 
>>   nat  = 122,
>>   ntyp = 4,
>>   ecutwfc = 70.0,
>> /
>> 
>> 
>> &ELECTRONS
>>   emass = 400.d0,
>>   emass_cutoff = 2.5d0,
>>   orthogonalization = 'ortho',
>>   electron_dynamics = 'damp',
>>   electron_damping = 0.1
>>   ortho_max = 500,
>>   !electron_temperature = 'not_controlled',
>>   !electron_velocities = 'zero'
>> /
>> 
>> 
>> &IONS
>>   ion_dynamics = 'damp',
>>   ion_damping = 0.01,
>>   !ion_nstepe = 10,
>>   !ion_temperature = 'nose',
>>   !tempw = 350,
>>   !fnosep = 70,
>>   !ion_velocities = 'zero'
>> /
>> 
>> 
>> 
>> 
>> ATOMIC_SPECIES
>> 
>> 
>>  O 16.0d0  O.pbe-hgh.UPF
>>  H 1.0d0   H.pbe-hgh.UPF 
>>  C 12.0d0  C.pbe-hgh.UPF 
>>  N 14.0d0  N.pbe-hgh.UPF
>> 
>> 
>> ATOMIC_POSITIONS {angstrom}
>> 
>> 
>>    C     -0.244144     1.783022    -1.335832 
>>    C     -2.567204    -0.241389     5.783803 
>>    N     -1.038197    -1.652589     5.418683 
>>    C     -6.336078    -1.532299    -1.532562 
>>    O     -5.122808    -0.424258    -2.279843 
>>    N      3.987336     0.412822    -1.692063 
>>    C      0.552282    -0.043486     0.368085 
>>    O      1.73575      0.043368     0.476670 
>>    O      1.126133    -1.181319     1.757325 
>>    H     -0.844512    -1.781630    -0.580034 
>>    H     -1.992345    -1.968023     0.581635 
>>    H     -1.547999    -0.018973     1.618910 
>>    H     -1.017864     1.793541     0.067225 
>>    H     -2.180408     0.669590    -0.675764 
>>    H      1.490782     1.185685    -2.387313 
>>    H      1.070763     1.992771    -0.909308 
>>    H      0.490233    -1.888235     1.458829 
>>    O      5.160929     1.400891    -4.018523 
>>    H      5.585303     1.845186    -4.767840 
>>    H      5.903707     1.074826    -3.488501 
>>    O      6.523016    -2.630620    -1.333026 
>>    H      6.731773    -1.730291    -1.624223 
>>    H      6.238875    -2.519196    -0.413345 
>> ( ........)
>> 
>> 
>> 
>> 
>> Alex.
>> Thanks to all.
>> _______________________________________________
>> Pw_forum mailing list
>> Pw_forum at pwscf.org
>> http://pwscf.org/mailman/listinfo/pw_forum
>
>-- 
>Paolo Giannozzi, Dept. Chemistry&Physics&Environment, 
>Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
>Phone +39-0432-558216, fax +39-0432-558222 
>
>
>
>
>
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