[Pw_forum] Pseudopotential for indium

Pascal Boulet pascal.boulet at univ-amu.fr
Thu Dec 7 23:40:30 CET 2017


Dear Nicola,

Yes, indium is metallic.  The parameters I use to treat it are:
  occupations    = 'smearing',
  smearing       = 'cold',
  degauss        = 0.02,

There are 13 valence electrons in indium and 34 Kohn-Sham states. I have checked the band occupations for all the k-points; at least the two uppermost bands are empty, in most case even more.

Here are the results of my tests.

Exp. : 3.2449 x 3.2449 x 4.9420 angstroms

--------------------------------------------------------------------------
K-points     | Ecut/Ry | Ecutrho/Ry |   PSP     | Fntal | cell parameters 
--------------------------------------------------------------------------
8x8x8=40         120       1200       PAW nrel     PBE    3.2168 x 5.3095
8x8x8=40         150        600        NC nrel     PBE    3.2213 x 5.3194
8x8x8=40          50        500       PAW rel+SO    PZ    3.0786 x 5.0095
8x8x8=40         120       1200       PAW rel+SO    PZ    3.1032 x 5.0938
12x12x12=126      50        500       PAW rel+SO    PZ    3.1692 x 4.7429
16x16x16=288      50        500       PAW rel+SO    PZ    3.1340 x 4.8412
12x12x12=126     120       1200       PAW rel+SO    PZ    3.2094 x 4.7811
16x16x16=288     120       1200       PAW rel+SO    PZ    3.1647 x 4.9076

The best result is the last one. So the PAW of In is very hard (!) and need a huge amount of k-points… This is the first time I see this problem with a PAW PSP of the library… 

Thank you all for your hints.
Pascal

Pascal Boulet
—
Professor in computational chemistry - DEPARTEMENT OF CHEMISTRY
Aix-Marseille University - ST JEROME - Avenue Escadrille Normandie Niemen - F-13013 Marseille - FRANCE
Tél: +33(0)4 13 55 18 10 - Fax : +33(0)4 13 55 18 50
Site : http://madirel.univ-amu.fr/pages_web_BOULET_PASCAL/infos - Email : pascal.boulet at univ-amu.fr




Le 7 déc. 2017 à 17:35, Nicola Marzari <nicola.marzari at epfl.ch> a écrit :

> 
> Thanks Pascal - this is metallic,
> and you are using smearing, correct? Something like 0.02 Ry, and
> Marzari-Vanderbilt cold smearing?
> 
> Also, how many electrons does your pseudo have? Do you have enough bands
> (i.e. are the top ones empty)?
> 
> nicola
> 
> 
> 
> On 07/12/2017 14:23, Pascal Boulet wrote:
>> Dear Nicola,
>> You are right I also noticed that the ‘pseudo' state energies match very well the AE ones.
>> Regarding the alloys Vegard’s law should hold according to experimental data. We are indeed using supercells.
>> I am currently running tests on pure indium. As mentioned by Paolo, the mass is irrelevant in the results for static calculations (as expected!). I have preliminary results with relativistic+SO calculation that are a bit better:
>> 3.0786 x 3.0786 x 5.0095
>> Recall:
>> exp.: 3.2449 x 3.2449 x 4.9420
>> previous calc.: 3.2168 x 3.2168 x 5.3095
>> This is obtained with Ecut=50 Ry Ecutrho=500 Ry, 8x8x8 kpts=40 kpts
>> With these parameters c improves substantially (1.4% off) but a and c worsen a bit (5% off).
>> I am running a test with more kpts first. In a second step I will increase Ecut and Ecutrho and will report to the forum.
>> Pascal
>> Pascal Boulet
>>>> /Professor in computational chemistry - DEPARTEMENT OF CHEMISTRY/
>> Aix-Marseille University - ST JEROME - Avenue Escadrille Normandie Niemen - F-13013 Marseille - FRANCE
>> Tél: +33(0)4 13 55 18 10 - Fax : +33(0)4 13 55 18 50
>> Site : http://madirel.univ-amu.fr/pages_web_BOULET_PASCAL/infos - Email : pascal.boulet at univ-amu.fr <mailto:pascal.boulet at univ-amu.fr>
>> Le 6 déc. 2017 à 23:24, Nicola Marzari <nicola.marzari at epfl.ch <mailto:nicola.marzari at epfl.ch>> a écrit :
>>> 
>>> Dear Pascal,
>>> 
>>> 
>>> the comparison with all-electron calculations looks good to me - see
>>> here for tests and for the other pseudos:
>>> http://materialscloud.org/sssp/results/In_conv_patt.png
>>> 
>>> Comparing with expts is more delicate -  c/a with PBE is
>>> quite a bit off e.g. in ferroelectric perovskites.
>>> 
>>> Re the alloy, how are you constructing the intermediate concentrations?
>>> Supercells? (Vegard law should hold)
>>> 
>>> nicola
>>> 
>>> On 06/12/2017 23:03, Paolo Giannozzi wrote:
>>>> You mean: the value 49.0 here?
>>>> ATOMIC_SPECIES
>>>> In 49.0 In.pbe-dn-kjpaw_psl.1.0.0.UPF
>>>> Iit is used only by molecular dynamics, not by structural optimization.
>>>> 
>>>> I don't remember In to be an especially nasty element, at least for
>>>> simple III-V compounds like InAs. I would examine the effect of a denser
>>>> k-point grid, and of spin-orbit
>>>> 
>>>> Paolo
>>>> 
>>>> 
>>>> On Wed, Dec 6, 2017 at 10:46 PM, Saif Ullah <kiterunner7 at gmail.com
>>>> <mailto:kiterunner7 at gmail.com>> wrote:
>>>> 
>>>>    Dear Boulet,
>>>> 
>>>>    I think I found where the error is. You are using the atomic number
>>>>    of In instead of its atomic mass.
>>>> 
>>>>    Regards
>>>>    Saif
>>>>    Department of physics, UFJF, Brazil
>>>> 
>>>> 
>>>> 
>>>>    On Wed, Dec 6, 2017 at 6:45 PM, Pascal Boulet
>>>>    <pascal.boulet at univ-amu.fr <mailto:pascal.boulet at univ-amu.fr>> wrote:
>>>> 
>>>>        Thanks Lorenzo for the suggestion. I have tried with Ecut=120 Ry
>>>>        and Ecutrho=1200 Ry. I get a slightly better result (but c is
>>>>        still very bad):
>>>>        3.2168 x 3.2168 x 5.3095
>>>> 
>>>>        as compared with:
>>>>        exp.: 3.2449 x 3.2449 x 4.9420 angström
>>>>        previous calc.: 3.2715 x 3.2715 x 5.4541 angström
>>>> 
>>>> 
>>>>        Best,
>>>> 
>>>>        Pascal Boulet
>>>>>>>>        /Professor in computational chemistry - DEPARTEMENT OF CHEMISTRY/
>>>>        Aix-Marseille University - ST JEROME - Avenue Escadrille
>>>>        Normandie Niemen - F-13013 Marseille - FRANCE
>>>>        Tél: +33(0)4 13 55 18 10 <tel:+33%204%2013%2055%2018%2010> - Fax
>>>>        : +33(0)4 13 55 18 50 <tel:+33%204%2013%2055%2018%2050>
>>>>        Site : http://madirel.univ-amu.fr/pages_web_BOULET_PASCAL/infos
>>>>        <http://madirel.univ-amu.fr/pages_web_BOULET_PASCAL/infos> -
>>>>        Email : pascal.boulet at univ-amu.fr <mailto:pascal.boulet at univ-amu.fr>
>>>> 
>>>> 
>>>> 
>>>> 
>>>>        Le 6 déc. 2017 à 18:54, Lorenzo Paulatto <paulatz at gmail.com
>>>>        <mailto:paulatz at gmail.com>> a écrit :
>>>> 
>>>>>        Hello,
>>>>>        can you try with a much higher cutoff (100 Ry or more) and see
>>>>>        if the lattice parameter improves? I've noticed that sometimes
>>>>>        pslibrary pseudos are much a harder than they look, especially
>>>>>        when converging stress
>>>>> 
>>>>>        Cheers
>>>>> 
>>>>>        --
>>>>>        Lorenzo Paulatto
>>>>>        Written on a virtual keyboard with real fingers
>>>>> 
>>>>>        On Dec 6, 2017 18:32, "Pascal Boulet"
>>>>>        <pascal.boulet at univ-amu.fr <mailto:pascal.boulet at univ-amu.fr>>
>>>>>        wrote:
>>>>> 
>>>>>            Dear all,
>>>>> 
>>>>>            We are working on some In-containing semiconductors
>>>>>            M(1-x)In(x)L. M is supposed to be a smaller atom than In.
>>>>>            We are facing the problem that when we vary x from 0 to 1
>>>>>            the cell parameters is decreasing instead of increasing.
>>>>>            Although this may happen, it should not be the case here
>>>>>            since ‘pure’ ML has a smaller cell parameter than ‘pure’ InL.
>>>>> 
>>>>>            We have run some calculations on crystal indium using the
>>>>>            PSL library pseudo potentials (both PAW and USPP). one of
>>>>>            the calculated cell parameters are miles away from the
>>>>>            experimental ones:
>>>>>            exp.: 3.2449 x 3.2449 x 4.9420 angström
>>>>>            calc.: 3.2715 x 3.2715 x 5.4541 angström
>>>>> 
>>>>>            Does anyone have tested the In pseudo potentials of the
>>>>>            PSL library or faced this problem with indium?
>>>>> 
>>>>>            Thank you for your help and time.
>>>>> 
>>>>>            Best regards
>>>>> 
>>>>>            PS1. here are some information from the input file:
>>>>> 
>>>>>             calculation    = 'vc-relax’,
>>>>>              etot_conv_thr  = 1d-7,
>>>>>              forc_conv_thr  = 5d-5,
>>>>>              ibrav          = 0,
>>>>>               nat            = 2,
>>>>>              ntyp           = 1,
>>>>>              ecutwfc        = 45.d0,
>>>>>              ecutrho        = 450.d0,
>>>>>              nbnd = 18
>>>>>            &ELECTRONS
>>>>>              conv_thr       = 1d-8,
>>>>>            &CELL
>>>>>              press_conv_thr = 0.01d0,
>>>>>              cell_factor    = 1.5,
>>>>>            ATOMIC_SPECIES
>>>>>            In 49.0 In.pbe-dn-kjpaw_psl.1.0.0.UPF
>>>>>            K_POINTS automatic
>>>>>            8 8 4 1 1 1
>>>>>            CELL_PARAMETERS angstroms
>>>>>            3.2449 0. 0.
>>>>>            0. 3.2449 0.
>>>>>            0. 0. 4.9420
>>>>>            ATOMIC_POSITIONS crystal
>>>>>                In           0.00000000    0.00000000    0.00000000
>>>>>                In           0.50000000    0.50000000    0.50000000
>>>>> 
>>>>>            PS2. And some from the output:
>>>>> 
>>>>>                bfgs converged in  18 scf cycles and  15 bfgs steps
>>>>>                 (criteria: energy <  1.0E-07 Ry, force <
>>>>>             5.0E-05Ry/Bohr, cell <  1.0E-02kbar)
>>>>>            CELL_PARAMETERS (angstrom)
>>>>>               3.271466870   0.000000000   0.000000000
>>>>>               0.000000000   3.271466870   0.000000000
>>>>>               0.000000000   0.000000000   5.454067219
>>>>>            !    total energy              =    -821.46750731 Ry
>>>>>            total   stress  (Ry/bohr**3)                   (kbar)
>>>>>            P=    0.30
>>>>> 
>>>>>            Pascal Boulet
>>>>>>>>>>            /Professor in computational chemistry - DEPARTEMENT OF
>>>>>            CHEMISTRY/
>>>>>            Aix-Marseille University - ST JEROME - Avenue Escadrille
>>>>>            Normandie Niemen - F-13013 Marseille - FRANCE
>>>>>            Tél: +33(0)4 13 55 18 10 <tel:04%2013%2055%2018%2010> -
>>>>>            Fax : +33(0)4 13 55 18 50 <tel:04%2013%2055%2018%2050>
>>>>>            Site :
>>>>>            http://madirel.univ-amu.fr/pages_web_BOULET_PASCAL/infos
>>>>>            <http://madirel.univ-amu.fr/pages_web_BOULET_PASCAL/infos> -
>>>>>            Email : pascal.boulet at univ-amu.fr
>>>>>            <mailto:pascal.boulet at univ-amu.fr>
>>>>> 
>>>>> 
>>>>> 
>>>>> 
>>>>> 
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>>>>> 
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>>>> 
>>>> -- 
>>>> 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
>>>> 
>>>> 
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>>> 
>>> -- 
>>> ----------------------------------------------------------------------
>>> Prof Nicola Marzari, Chair of Theory and Simulation of Materials, EPFL
>>> Director, National Centre for Competence in Research NCCR MARVEL, EPFL
>>> http://theossrv1.epfl.ch/Main/Contact http://nccr-marvel.ch/en/project
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> 
> 
> -- 
> ----------------------------------------------------------------------
> Prof Nicola Marzari, Chair of Theory and Simulation of Materials, EPFL
> Director, National Centre for Competence in Research NCCR MARVEL, EPFL
> http://theossrv1.epfl.ch/Main/Contact http://nccr-marvel.ch/en/project

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