[Pw_forum] SCF do not converge

Arles V. Gil Rebaza arvifis at gmail.com
Wed Jul 20 16:18:13 CEST 2016


Dear Regina, Pt have a FCC crystal structure, so if you are studing Pt(111)
surface, you need 3 layer to have 1 slab, i.e. to describe the Pt(111)
surface in general you should use 3, 6, 9 or 12, .etc.. layers. In the case
of Pt(100) surface are 2, 4, 6,.. layers. May be this is the reason that
your calculation does not converge.

Best

Dr. Arles V. Gil Rebaza
Instituto de Física La Plata
La Plata - Argentina

2016-07-20 10:34 GMT-03:00 Regina Lelis de Sousa <rlsousa at mail.uft.edu.br>:

> Dear all,
> I am studying Pt(111) and Pt(100) surfaces (using a slab model) with
> PWSCF. I ran a structural relaxations for slabs containing 4 - 9 atomic
> planes (layers) and everything was fine. In all calculations a vacuum
> region of the order of 15 Angstroms was  used. However, in the calculations
> with 10 atomic planes or more the SCF procedure does not converge and i do
> not understand the reason. I did some changes on SCF procedure (for
> example: I tested cg method among other things). Does anyone notice some
> mistake with the input file or with my atomic coordinates?  Any help would
> be appreciated.
>
>
>  The  inputs and outputs are:
>
> 1 - First Try:
> $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
> &control
>     calculation = 'relax'
>     restart_mode='from_scratch',
>     prefix='Pt_100_12_layers_15_vacuo',
>     tprnfor = .true.,
>     tstress =.true.,
>     verbosity ='high',
>     pseudo_dir = '/home/rlsousa/Pseudopot',
>  /
>  &system
>     ibrav=  6,
> A = 2.831157456,
> C=37.2,
>     nat=  12,
>     ntyp= 1,
>     ecutwfc =35.0,
>     ecutrho = 350.0,
>     occupations='smearing',
>     smearing='marzari-vanderbilt',
>     degauss=0.01, !I tested this.
>  /
>  &electrons
>     mixing_beta = 0.7,
>     conv_thr =  1.0d-8
> electron_maxstep = 600,
>  /
> &ions
> /
> ATOMIC_SPECIES
> Pt  195.084 Pt.pbe-nd-rrkjus.UPF
> ATOMIC_POSITIONS {angstrom}
> Pt    0.000000    0.000000    0.000000
> Pt    1.414214    1.414214    2.000000
> Pt    0.000000    0.000000    4.000000
> Pt    1.414214    1.414214    6.000000
> Pt    0.000000    0.000000    8.000000
> Pt    1.414214    1.414214    10.000000
> Pt    0.000000    0.000000    12.000000
> Pt    1.414214    1.414214    14.000000
> Pt    0.000000    0.000000    16.000000
> Pt    1.414214    1.414214    18.000000
> Pt    0.000000    0.000000    20.000000
> Pt    1.414214    1.414214    22.000000
> K_POINTS AUTOMATIC
> 16 16 1 1 1 1
> $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
> OUTPUT:
>
>      Program PWSCF v.5.0.1 starts on  3Mar2016 at  1:58: 2
> ...
>
> ...
>
>      Self-consistent Calculation
>
>      iteration #  1     ecut=    35.00 Ry     beta=0.70
>      Davidson diagonalization with overlap
>      ethr =  1.00E-02,  avg # of iterations =  4.0
>
>      total cpu time spent up to now is      212.7 secs
>
>      total energy              =   -1037.38592080 Ry
>      Harris-Foulkes estimate   =   -1039.73360971 Ry
>      estimated scf accuracy    <       2.83017780 Ry
>
>      iteration #  2     ecut=    35.00 Ry     beta=0.70
>      Davidson diagonalization with overlap
>      ethr =  2.36E-03,  avg # of iterations =  8.9
>
>      total cpu time spent up to now is      627.5 secs
>
>      total energy              =   -1004.47885510 Ry
>      Harris-Foulkes estimate   =   -1113.67210149 Ry
>      estimated scf accuracy    <    4035.50057863
>
> ...
>
>
>      iteration #600     ecut=    35.00 Ry     beta=0.70
>      Davidson diagonalization with overlap
>      ethr =  2.92E-05,  avg # of iterations = 11.5
>
>      total cpu time spent up to now is   250301.6 secs
>
>      total energy              =   -1025.14170975 Ry
>      Harris-Foulkes estimate   =   -1050.93732899 Ry
>      estimated scf accuracy    <     312.87625423 Ry
>
>      End of self-consistent calculation
>
>      convergence NOT achieved after 600 iterations: stopping
>
>
>
> ===================================================================================
> =   BAD TERMINATION OF ONE OF YOUR APPLICATION PROCESSES
> =   EXIT CODE: 1
> =   CLEANING UP REMAINING PROCESSES
> =   YOU CAN IGNORE THE BELOW CLEANUP MESSAGES
>
> ===================================================================================
>
>
> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
> 2 - Second Try:
> I did:
>  &electrons
> diagonalization='cg'
>     mixing_beta = 0.5,
>     conv_thr =  1.0d-8
> electron_maxstep = 300,
>
> and this work fine only for Pt(100) with 10 atomic plane.
>
> $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
>
> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
> 3 - Third Try:
> For Pt(111) with 10 atomic planes:
> $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
>  &control
>     calculation = 'relax'
>     restart_mode='from_scratch',
>     prefix='Pt_111_10_layers',
>     tprnfor = .true.,
>     tstress =.true.,
>     verbosity ='high',
>     pseudo_dir = '/home/rlsousa/pseudo/'
>  /
>  &system
>     ibrav=  4,
> A = 2.831157456,
> C=36.0,
>     nat=  10,
>     ntyp= 1,
>     ecutwfc =35.0,
>     ecutrho = 350.0,
>     occupations='smearing',
>     smearing='marzari-vanderbilt',
>     degauss=0.01,
>  /
>  &electrons
>     mixing_beta = 0.7,
>     conv_thr =  1.0d-8
> electron_maxstep = 600,
>  /
> &ions
> /
> ATOMIC_SPECIES
> Pt  195.084 Pt.pbe-nd-rrkjus.UPF
> ATOMIC_POSITIONS {angstrom}
> Pt -0.000000000 -0.000000000 -20.784609691
> Pt 0.000000000 -0.000000000 -13.856406461
> Pt 0.000000000 -0.000000000 -6.928203230
> Pt 0.000000000 0.000000000 0.000000000
> Pt 1.414213562 0.816496581 -16.165807537
> Pt 1.414213562 0.816496581 -9.237604307
> Pt 1.414213562 0.816496581 -2.309401077
> Pt -0.000000000 1.632993162 -18.475208614
> Pt -0.000000000 1.632993162 -11.547005384
> Pt -0.000000000 1.632993162 -4.618802154
> K_POINTS AUTOMATIC
> 16 16 1 1 1 1
> $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
> And the output is:
> $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
>      Self-consistent Calculation
>
>      iteration #  1     ecut=    35.00 Ry     beta=0.70
>      Davidson diagonalization with overlap
>      ethr =  1.00E-02,  avg # of iterations =  3.7
>
>      total cpu time spent up to now is      619.8 secs
>
>      total energy              =    -864.90667968 Ry
>      Harris-Foulkes estimate   =    -866.46381391 Ry
>      estimated scf accuracy    <       1.92161923 Ry
>
>      iteration #  2     ecut=    35.00 Ry     beta=0.70
>      Davidson diagonalization with overlap
>      ethr =  1.92E-03,  avg # of iterations =  8.8
>
>      total cpu time spent up to now is     1789.4 secs
>
>      total energy              =    -834.69092069 Ry
>      Harris-Foulkes estimate   =    -912.73406647 Ry
>      estimated scf accuracy    <    3297.67106012 Ry
>     iteration #154     ecut=    35.00 Ry     beta=0.70
>      Davidson diagonalization with overlap
>      ethr =  8.37E-05,  avg # of iterations =  7.2
>
>      negative rho (up, down):  0.577E-07 0.000E+00
>
>      total cpu time spent up to now is   143089.7 secs
>
>      total energy              =    -862.54326840 Ry
>      Harris-Foulkes estimate   =    -876.81955048 Ry
>      estimated scf accuracy    <     354.34333068 Ry
>
>      iteration #155     ecut=    35.00 Ry     beta=0.70
>      Davidson diagonalization with overlap
> $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
>
> 4 - fourth Try:
> The atomic positions for input file was optimized with a PCFF force field:
> a - For Pt(100) with 16 atomic planes, the atomic positions for input were:
> Pt 0.000001863 -0.000006550 1.917081940
> Pt -0.000000583 -0.000002969 5.858730954
> Pt -0.000001806 0.000000728 9.775507899
> Pt -0.000003453 0.000006845 13.688807549
> Pt -0.000001863 0.000006007 17.601709335
> Pt -0.000000324 0.000000339 21.516053222
> Pt 0.000003440 -0.000003229 25.439026038
> Pt 0.000005016 -0.000002994 29.455726011
> Pt 1.382821195 1.382814326 -0.121704445
> Pt 1.382818575 1.382816058 3.895001445
> Pt 1.382817093 1.382818978 7.817973036
> Pt 1.382816565 1.382824166 11.732314256
> Pt 1.382814960 1.382827050 15.645213637
> Pt 1.382818406 1.382822391 19.558517247
> Pt 1.382820459 1.382816862 23.475296312
> Pt 1.382823964 1.382815499 27.416943612
>
> But I get the same result.
> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
> 5 - fifth try - I did not have any throuble for these cases.
> a - For Pt(100) with 9 atomic planes:
> $$$$$$$$$$$$$$$$$$$$$$$$$$$
> .....
>  &system
>     ibrav=  6,
> A = 2.831157456,
> C=33.2,
>     nat=  9,
>     ntyp= 1,
>     ecutwfc =35.0,
>     ecutrho = 350.0,
>     occupations='smearing',
>     smearing='marzari-vanderbilt',
>     degauss=0.01,
>  /
>  &electrons
> diagonalization='cg'
>     mixing_beta = 0.5,
>     conv_thr =  1.0d-8
> electron_maxstep = 300,
>  /
> &ions
> /
> ATOMIC_SPECIES
> Pt  195.084 Pt.pbe-nd-rrkjus.UPF
> ATOMIC_POSITIONS {angstrom}
> Pt 0.000000000 -0.000000000 2.001930636
> Pt 0.000000000 -0.000000000 6.005791907
> Pt 0.000000000 -0.000000000 10.009653178
> Pt 0.000000000 -0.000000000 14.013514450
> Pt 1.415578728 1.415578728 -0.000000000
> Pt 1.415578728 1.415578728 4.003861271
> Pt 1.415578728 1.415578728 8.007722543
> Pt 1.415578728 1.415578728 12.011583814
> Pt 1.415578728 1.415578728 16.015445086
>
> .....
> $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
>
> Atomic positions for Pt(100) with 9 atomic planes:
> $$$$$$$$$$$$$$$$$$$$$$$$$$$
> b - For Pt(111) with 9 atomic planes:
>  &system
>     ibrav=  4,
> A = 2.831157456,
> C=36.0,
>     nat=  9,
>     ntyp= 1,
>     ecutwfc =35.0,
>     ecutrho = 350.0,
>     occupations='smearing',
>     smearing='marzari-vanderbilt',
>     degauss=0.01,
>  /
>  &electrons
>     mixing_beta = 0.7,
>     conv_thr =  1.0d-8
> electron_maxstep = 600,
>  /
> &ions
> /
> ATOMIC_SPECIES
> Pt  195.084 Pt.pbe-nd-rrkjus.UPF
> ATOMIC_POSITIONS {angstrom}
> Pt 0.000000000 -0.000000000 -13.856406461
> Pt 0.000000000 -0.000000000 -6.928203230
> Pt 0.000000000 0.000000000 0.000000000
> Pt 1.414213562 0.816496581 -16.165807537
> Pt 1.414213562 0.816496581 -9.237604307
> Pt 1.414213562 0.816496581 -2.309401077
> Pt -0.000000000 1.632993162 -18.475208614
> Pt -0.000000000 1.632993162 -11.547005384
> Pt -0.000000000 1.632993162 -4.618802154
>
> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
>
> Thanks in advance,
> regards
>
> R. Lelis-Sousa.
> UFT/TO/Brazil.
>
>
>
> --
> Tenha uma ótima semana,
>
> Atenciosamente,
>
>
> Dra. Regina Lélis de Sousa
> Professor Adjunto -- Universidade Federal do Tocantins
> Campus de Araguaína
> Rua Paraguai SN -- Esquina com a Urixamas
> Telefone: +55(63)2112-2283
> Caixa Postal 132
> CEP: 77.838-824
> Tocantins.
> "Success is knowing that you have done your best and have exploited your
> God-given or gene-given abilities to the next maximum extent. More than
> this, no
> one can do...".  Prof. Alan Graham MacDiarmid
>
>
> _______________________________________________
> Pw_forum mailing list
> Pw_forum at pwscf.org
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>



-- 
###--------->   Arles V.   <---------###
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