[Wien] Questions about difference electron density map

Ding Peng ding.peng at monash.edu
Sat May 2 13:11:16 CEST 2020


Dear Prof Peter Blaha and other WIEN2k experts,

Many thanks for your advice. Your explanation is very clear and I can
understand most of them. But I still get some questions to ask:
By following your advices, I've checked the band ranges in output2 and they
are :

--------------------------------Parts of
output2--------------------------------
 Bandranges (emin - emax) and occupancy:
band       1   -6.9938079252   -6.9938068925      0.000000D+00
band       2   -6.9938078129   -6.9938067789      0.000000D+00
band       3   -6.9938075730   -6.9938067050      0.000000D+00
band       4   -6.9922185272   -6.9922171063      0.000000D+00
band       5   -6.9922181557   -6.9922169918      0.000000D+00
band       6   -1.8334038234   -1.8299238783      0.000000D+00
band       7   -0.5941215608   -0.5602216598      0.000000D+00
band       8   -0.5816946085   -0.5557101544      0.000000D+00
band       9   -0.5751014423   -0.5522058796      0.000000D+00
band      10   -0.3523559948   -0.2915563417      0.000000D+00
band      11    0.0102820741    0.1817704795      0.100000D+01
band      12    0.0568458849    0.2210156808      0.100000D+01
band      13    0.0595422391    0.2450134176      0.100000D+01
band      14    0.2549168642    0.4253204770      0.100000D+01
band      15    0.2959704288    0.4580082799      0.100000D+01
band      16    0.2959704288    0.5242514698      0.100000D+01
band      17    0.4617620761    0.6404131757      0.100000D+01
band      18    0.5009561953    0.6404131757      0.100000D+01
band      19    0.5254029432    0.6639874358      0.100000D+01
band      20    0.6537470324    0.8122537757      0.797587D+00
band      21    0.7673471494    0.8165161597      0.173604D+00
band      22    0.7673471501    0.8198106031      0.288073D-01
band      23    0.8178909130    0.8291818636      0.132733D-05
band      24    0.8183879986    0.8332577081      0.540254D-06
band      25    0.8199523093    0.8399415204      0.118161D-06
band      26    0.8207016006    0.8472810193      0.126056D-07
band      27    0.8419422638    1.0643898132      0.106408D-11
band      28    0.8705920751    1.0643898132      0.134771D-18
band      29    0.9163369086    1.0782104048      0.548461D-28
band      30    0.9531801987    1.0815012496      0.441451D-36
band      31    0.9743340140    1.0989292747      0.368350D-41
band      32    1.0215704771    1.1835437911      0.656471D-51
band      33    1.0619410941    1.2660369506      0.104602D-59
band      34    1.0710750831    1.3480206869      0.821212D-62
band      35    1.1506050865    1.3510053898      0.581976D-79
band      36    1.2479599705    1.3842653024      0.426690-100
band      37    1.3008264765    1.4541416473      0.475526-112
band      38    1.3299186129    1.5361870335      0.224981-118
band      39    1.3695104772    1.6935789032      0.566326-127
band      40    1.4222530569    1.6935789033      0.582576-138
band      41    1.4222530569    1.7479839170      0.199634-138
band      42    1.4893656739    1.8477650284      0.159998-152
band      43    1.5321159806    1.8542669965      0.277803-162
band      44    1.5321159807    1.8888178555      0.277798-162
band      45    1.7205342860    1.9773592650      0.101492-202
band      46    1.7387893640    1.9830659978      0.110619-206
band      47    1.8578879947    1.9842039715      0.162499-232
band      48    1.9141741359    2.1423257410      0.197786-244
band      49    1.9912888985    2.1504448218      0.164223-261
band      50    2.0213087100    2.2245846366      0.494312-268
band      51    2.0776021129    2.2517009300      0.394027-280
band      52    2.1342747050    2.2915972500      0.147580-292
band      53    2.1884404034    2.2897770771      0.440079-304
band      54    2.2227045813    2.2925611935      0.000000D+00
band      55    2.2354676016    2.2928884066      0.000000D+00

 eseper below EF  0.500000000000000
 eseper minimum gap  5.000000000000000E-002
 qtlsave setting:             1
 Energy to separate semicore and valence states: -3.971792594507138E-002

:NOE  : NUMBER OF ELECTRONS          =  40.000

:FER  : F E R M I - ENERGY(FERMI-SM.)=   0.7942672487
 wmist   19.9999999977898
     FORCE-CALCULATION: T
------------------------------------------------------------------------------------------

Compared to the information in case.scf1, I was thinking the Emin should be
set slightly above the energy band 10, which is from -0.3524 to -0.2916
(please correct me if I'm wrong). Does that mean the Emin of the whole
valence electrons should be set slightly above Emax of energy band 10,
which is -0.2916?

Many thanks,
Ding

On Mon, 27 Apr 2020 at 16:25, Peter Blaha <pblaha at theochem.tuwien.ac.at>
wrote:

> For a difference density it is of course necessary that you treat the
> same states in the solids and in the atom.
> While in an atom this is fairly simple, because each state is classified
> by n,l,m (or kappa), for the solid we are missing the "n". We know
> easily the "l" (s,p,d,f), but not the principal quantum number n (like
> 4p or 5p).
>
> This can be only be done by comparising with the atom, via the
> "knowledge" what a chemist would call "valence and core" states and via
> the energies of these states.
>
> a) execute:  x lstart -sigma
> b) This creates a case.inst_sigma  input file, where the "P" indicates
> to you, which atomic densities are plotted.
> c) Look into case.outputst to see their energies (and in particular
> those of lower lying states (semi-core states) which have a "T"
> indicating that they are included in the solid as "valence" and some of
> them must be cut away.
> d) now look at your scf1 file (both the E-parameters as you showed us,
> but also the eigenvalues. Sometimes also the band-ranges in case.output2
> are helpful.:
>
>  >            ATOMIC SPHERE DEPENDENT PARAMETERS FOR ATOM  Ce
>  > :e__0001: OVERALL ENERGY PARAMETER IS    0.5943
>  >            OVERALL BASIS SET ON ATOM IS LAPW
>  > :E2_0001: E( 2)=    0.5943
>  >               APW+lo
>  > :E2_0001: E( 2)=   -6.9944   E(BOTTOM)=   -7.002   E(TOP)=   -6.987
> 1  2   170
>  >               LOCAL ORBITAL
>  > :E0_0001: E( 0)=    0.5943
>  >               APW+lo
>  > :E0_0001: E( 0)=   -1.8665   E(BOTTOM)=   -2.558   E(TOP)=   -1.175
> 4  5   176
>  >               LOCAL ORBITAL
>  > :E1_0001: E( 1)=    0.9943
>  >               APW+lo
>  > :E1_0001: E( 1)=   -0.4363   E(BOTTOM)=   -1.448   E(TOP)=    0.575
> 3  4   197
>  >               LOCAL ORBITAL
>  > :E3_0001: E( 3)=    0.6959   E(BOTTOM)=    0.466   E(TOP)=    0.925
> 0  1   123
>  >               APW+lo
>
> There should be Ce-d states around -7 Ry. Compare to the outpust file
> and you should see that these are 4d states (they are a bit lower in the
> atom) and thus "not valence", so they sould be cut away.
> You can do the same for Ce-s (5s) and finally 5p. The latter are at -1.6
> in the atom, but according to your list at -0.4 in the solid.
>
> e) So look again at the eigenvalues of case.output1 or the band ranges
> in output2 and you should find a solution:  most likely your   emin
> should be around -0.2 or so, i.e. in the "gap" between the real valence
> states (B-sp Ce-4f,5d,6sp) and the semicore states as identified above.
>
> PS: In some cases, the "automatic" procedure with "x lstart -sigma" may
> not work. Take a Ce-oxide, there will be O-2s states at LOWER energy
> than these Ce-5p states and you CANNOT select an EMIN, which "keeps" the
> O-2s but cuts away the Ce-5p. In such cases you have to explicitly
> include / exlude certain states in the atom (eg. edit case.inst_sigma
> and replace the "P" by "N" for the O-2s states, rerun:
> lstart lstart.def   (where lstart.def should contain: case.inst_sigma,
> not just case.inst).
>
> --
> Peter Blaha
> Inst.Materials Chemistry
> TU Vienna
> Getreidemarkt 9
> A-1060 Vienna
> Austria
> +43-1-5880115671
> _______________________________________________
> Wien mailing list
> Wien at zeus.theochem.tuwien.ac.at
> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
> SEARCH the MAILING-LIST at:
> http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://zeus.theochem.tuwien.ac.at/pipermail/wien/attachments/20200502/9aca2670/attachment.html>


More information about the Wien mailing list