[Pw_forum] Iron surfaces with molecules adsorbed give wrong KS orbital levels

Giuseppe Mattioli giuseppe.mattioli at ism.cnr.it
Thu Sep 7 11:49:06 CEST 2017


Dear Jibiao Li
First of all don't forget to sign the posts with name and scientific  
affiliation, please.

>    Fe   55.85000  Fe.pbe-sp-van_ak.UPF

You may not be aware of old nomenclature conventions (;-)), but this  
used to indicate a Vanderbilt's ultrasoft pseutopotential (van)  
generated by Axel Kohlmayer (ak) by using the PBE functional, and with  
*semicore* (different than *core*...) 3s and 3p states (sp) in  
valence. Such details can be found in the pseudopotential file header.  
Unfortunately, the inclusion of 3s and 3p semicore states is almost  
always mandatory to yield good results when dealing with first-row  
transition metals. This generally implies also that a higher cutoff is  
required for the calculation. I would expect something around

>                      ecutwfc = 35.0~40.0,
>                      ecutrho = 280.0~400.0,

depending on how tight you want to be on the accuracy of your results.
HTH
Giuseppe

Quoting Jibiao Li <jibiaoli at foxmail.com>:

> Dear QE experts,
>
>
> I am using iron as the surfaces to study the adsorption of several  
> molecules on Fe(100), but the calculations give totally wrong  
> eigenvalues at each kpoints, specifically I find core-level-like  
> orbitals ranging from -90 eV to -40 eV are occupied (red color). I  
> am very confused with the results. Why the ultrasoft pseudopotential  
> that only concerns valence electrons can produce KS orbital levels  
> deep into core states?
>
>
>           k = 0.0000 0.0000 0.0000 ( 11081 PWs)   bands (ev):
>
>
>    -86.4555 -86.4351 -86.4311 -86.4285 -86.2812 -86.2747 -86.2747 -86.2702
>    -85.9366 -85.8723 -85.8316 -85.8230 -85.7994 -85.7994 -85.7952 -85.7876
>    -52.5973 -52.5740 -52.5661 -52.5555 -52.4331 -52.4331 -52.4190 -52.4190
>    -52.4082 -52.3977 -52.3977 -52.3737 -52.3737 -52.3692 -52.3568 -52.3568
>    -52.2944 -52.2926 -52.2895 -52.2895 -52.2382 -52.2382 -52.2276 -52.2190
>    -52.0556 -51.9493 -51.9493 -51.9318 -51.9318 -51.9048 -51.9005 -51.8756
>    -51.8756 -51.8409 -51.8372 -51.8372 -51.7977 -51.7914 -51.7788 -51.7774
>    -51.7692 -51.7692 -51.7414 -51.7414 -51.7363 -51.7295 -51.7246 -51.7246
>    -20.3815 -10.6421  -5.1658  -4.5260  -4.4959  -4.4959  -2.7828  -2.2296
>     -2.2296  -2.2291  -2.1981  -1.9564  -1.9211  -1.9048  -1.8338  -1.5528
>     -1.5518  -1.3874  -1.3874  -1.3539  -1.2546  -1.0942  -1.0886  -1.0886
>     -0.9799  -0.9799  -0.7835  -0.7835  -0.7688  -0.7418  -0.6932  -0.5970
>     -0.5832  -0.5832  -0.2710  -0.2710  -0.2703  -0.1692  -0.1692  -0.1624
>     -0.1163  -0.0948  -0.0829  -0.0829   0.0226   0.0226   0.0947   0.0961
>      0.0961   0.1580   0.3102   0.4630   0.5612   0.6474   0.6534   0.6534
>      0.6549   0.7389   0.7508   0.7508   0.7714   0.8988   0.9951   0.9951
>      0.9958   1.0433   1.0513   1.0514   1.0633   1.0658   1.0745   1.1916
>      1.2102   1.2669   1.2669   1.2833   1.3949   1.4355   1.5104   1.5562
>      1.7028   1.7028   1.9613   1.9702   2.0733   2.0733   2.1154   2.1367
>      2.4228   2.4228   2.5083   2.5127   2.8478   2.8478   2.9137   3.1357
>      3.1357   3.9517   4.6210   4.6210   5.3729   5.4815   6.1669   6.4724
>      6.6335   6.6335   7.1807   7.3236   8.3786   8.3786   8.9910   9.1294
>      9.2428   9.4714   9.4714   9.5988   9.6995   9.7955  10.1252  10.3101
>     10.7330  10.7387  10.7415  11.0244  11.0244  11.2414  11.2414  11.6905
>     11.8792  11.9595  11.9898  11.9899  12.0296  12.0924  12.0924  12.3252
>     12.8738  13.1766  13.1766  13.4549  13.5446  13.9843  13.9843  14.1273
>     14.2108  14.2108  14.2360  14.3430  14.5855  14.7269  14.7269  14.9475
>     15.2949  15.2949  15.3500  15.4144  16.0735  16.0870  16.0870  16.3035
>     16.4139  16.4139  16.4399  16.5250  16.5250  16.5695  17.4772  17.5341
>     17.5740  17.7219  17.7761  17.7761  17.9196  18.0882  18.1237  18.1237
>
> ...
>
>
>  &CONTROL
>                  calculation = 'relax' ,
>                 restart_mode = 'from_scratch' ,
>                       outdir = '/home/jibiao/Calc/NO_Fe100/H/' ,
>                   pseudo_dir = '/home/jibiao/Codes/pseudo/' ,
>                       prefix = 'ads' ,
>  /
>  &SYSTEM
>                        ibrav = 6,
>                    celldm(1) = 10.847032278,
>                    celldm(3) = 3.28,
>                          nat = 18,
>                         ntyp = 3,
>                      ecutwfc = 29 ,
>                      ecutrho = 180 ,
>                         nbnd = 240,
>                  occupations = 'smearing' ,
>                      degauss = 0.05D0 ,
>                     smearing = 'methfessel-paxton' ,
>                        nspin = 2 ,
>    starting_magnetization(1) = -0.1,
>    starting_magnetization(2) = -0.1,
>    starting_magnetization(3) = 2.9,
>             exxdiv_treatment = 'gygi-baldereschi' ,
>  /
>  &ELECTRONS
>                  mixing_beta = 0.2D0 ,
>              diagonalization = 'david' ,
>  /
>  &IONS
>  /
> ATOMIC_SPECIES
>     O   15.99900  O.pbe-van_ak.UPF
>     N   14.00700  N.pbe-van_ak.UPF
>    Fe   55.85000  Fe.pbe-sp-van_ak.UPF
> ATOMIC_POSITIONS angstrom
>     O      2.870068664    2.869938864    6.367012991    1  1  1
>     N      2.869956638    2.870042916    5.069510886    1  1  1
>    Fe      1.468603692    1.468610024    4.309291333    1  1  1
>    Fe      1.468616889    4.271383111    4.309347182    1  1  1
>    Fe      4.271399866    1.468600134    4.309263844    1  1  1
>    Fe      4.271389976    4.271396308    4.309291333    1  1  1
>    Fe      0.000000000    0.000000000    2.870000000    0  0  0
>    Fe      2.870000000    0.000000000    2.870000000    0  0  0
>    Fe      0.000000000    2.870000000    2.870000000    0  0  0
>    Fe      2.870000000    2.870000000    2.870000000    0  0  0
>    Fe      1.435000000    1.435000000    1.435000000    0  0  0
>    Fe      1.435000000    4.305000000    1.435000000    0  0  0
>    Fe      4.305000000    1.435000000    1.435000000    0  0  0
>    Fe      4.305000000    4.305000000    1.435000000    0  0  0
>    Fe      0.000000000    0.000000000    0.000000000    0  0  0
>    Fe      2.870000000    0.000000000    0.000000000    0  0  0
>    Fe      0.000000000    2.870000000    0.000000000    0  0  0
>    Fe      2.870000000    2.870000000    0.000000000    0  0  0
> K_POINTS automatic
>   4 4 1   0 0 0


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    Giuseppe Mattioli
    CNR - ISTITUTO DI STRUTTURA DELLA MATERIA
    v. Salaria Km 29,300 - C.P. 10
    I 00015 - Monterotondo Stazione (RM)
    Tel + 39 06 90672836 - Fax +39 06 90672316
    E-mail: <giuseppe.mattioli at ism.cnr.it>
    http://www.ism.cnr.it/en/staff/giuseppe-mattioli/
    ResearcherID: F-6308-2012





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