[QE-users] Regarding projected density of state

[Stefano Baroni]

As illogic as the naming convention may seem to some, it is not. The only feature a pseudo-wavefunction may me characterised with is the number of nodes of its radial component. In fact, pseudo-potentials are constructed exactly from the requirement that their lowest-lying states (which are node-less, as you can check at page 33 of your favorite quantum mechanics textbook) match the energy and the main lobe of the all-electron radial wave-function. Summarising: the lowest-lying atomic orbital of a pseudo-atom is always nodeless (by construction) the code labels it as 1s, 2p, 3d, etc. (n=1, l-0; n=2, l-1; n=3, l=2) the number of nodes is always n-l-1 (page 34 of the above textbook): you can check for yourself that it is 0 for 1s, 2p, 3d, 4f, etc. The code cannot know the radial quantum of the “real” orbital. It does know the angular quantum number and the number of nodes, though …

Hope this clarifies a little bit the whole matter.
SB

> On 9 Oct 2021, at 11:37, Giuseppe Mattioli <giuseppe.mattioli at ism.cnr.it> wrote:
> 
> 
> Dear user (please sign your posts with name and affiliation)
> 
> Orbitals are ordered according to pseudowavefunctions in the pseudopotential. It is cumbersome but not difficult to reorder them
> 
> 1s = 3s
> 2p = 3p
> 3s = 4s
> 4d = 3d
> 
> HTH
> Giuseppe
> 
> Quoting Satyasiban Dash ph19d005 <ph19d005 at smail.iitm.ac.in>:
> 
>> Dear Users
>> 
>> I need a little confirmation about nomenclature of outputfiles projwfc.x
>> generates. I was calculating PDOS of ZnO using pseudopotential from ps
>> library (PBE-GGA) . Its well known that ZnO has 4s,2s,2p and 3d orbital
>> but I am getting 1s,2p,3s,4d
>>  &CONTROL
>>                 calculation = 'scf' ,
>>                      outdir = 'job$tpdir' ,
>>                  pseudo_dir = '/lfs/usrhome/phd/ph19d005/pseudo' ,
>>                      prefix = 'zn' ,
>>                 lkpoint_dir = .false. ,
>>                   verbosity = 'low' ,
>>               etot_conv_thr = 1.0d-05 ,
>>               forc_conv_thr = 1.00d-04 ,
>> 
>> /
>> &SYSTEM
>>                       ibrav = 0,
>>                         nat = 4,
>>                        ntyp = 2,
>>                     ecutwfc = 40 ,
>>                     ecutrho = 500 ,
>>                     nbnd =30
>>                 occupations = 'smearing' ,
>>                 smearing ='gaussian'
>> /
>> &ELECTRONS
>>            electron_maxstep = 80,
>>                    conv_thr = 8.0000000000d-10 ,
>>                adaptive_thr = .false. ,
>>                 mixing_beta = 4.0000000000d-01 ,
>> /
>> CELL_PARAMETERS angstrom
>>     3.289102049    0.000000000    0.000000000
>>    -1.644551024    2.848445930    0.000000000
>>     0.000000000    0.000000000    5.306821000
>> ATOMIC_SPECIES
>>    O   15.99940  O.pbe-nl-kjpaw_psl.1.0.0.UPF
>>   Zn   65.38000  Zn.pbe-spn-kjpaw_psl.1.0.0.UPF
>> ATOMIC_POSITIONS crystal
>>   Zn      0.333333333    0.666666667    0.000548000
>>   Zn      0.666666667    0.333333333    0.500548000
>>    O      0.333333333    0.666666667    0.379762000
>>    O      0.666666667    0.333333333    0.879762000
>> K_POINTS automatic
>> 12 12 6 0 0 0
>> 
>> 
>> 
>> 
>> &PROJWFC
>>                      prefix = '$pref' ,
>>                      outdir =
>> '/lfs/usrhome/phd/ph19d005/scratch/job444857/job444857' ,
>>                     filpdos = 'zn_pdos.dat' ,
>>                     filproj = 'zn_proj.dat' ,
>>                      ngauss = 0,
>>                     degauss = 0.01 ,
>>                      DeltaE = 0.01 ,
>>                        Emin = -8 ,
>>                        Emax = 8 ,
>> /
>> 
>> Is it an indication error or something else
> 
> 
> 
> GIUSEPPE MATTIOLI
> CNR - ISTITUTO DI STRUTTURA DELLA MATERIA
> Via Salaria Km 29,300 - C.P. 10
> I-00015 - Monterotondo Scalo (RM)
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> E-mail: <giuseppe.mattioli at ism.cnr.it>
> 
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— 
Stefano Baroni - Trieste —  http://stefano.baroni.me <http://stefano.baroni.me/> 




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