[Wien] QTL quantization axis for Y_lm orbitals

gutowska at agh.edu.pl gutowska at agh.edu.pl
Tue Jan 17 20:02:52 CET 2023


Dear Lukasz,

the reason is that the (radial part) of the wave function is actually 
the sum of 5 terms.
As mentioned at http://www.wien2k.at/lapw/index.html in sector 
"LAPW+LO", the wave function is the sum of the atomic radial wave 
function and its energy derivative multiplied by the factors A_lm(k) and 
B_lm(k) respectively.
There is also an additional radial wave function called the local 
orbital with the coefficient C_lm(k).
Then comes the APW+lo method, where the local orbital is the sum of the 
new radial wave function and its energy derivative multiplied by the new 
coefficients A'_lm(k) and B'_lm(k), respectively.
This gives 5 coefficients: A_lm(k), B_lm(k), C_lm(k), A'_lm(k), B'_lm(k) 
in the case.almblm file. Each of them has a real and an imaginary part.
This is explained in Chapter 2 of the User's Guide.

what's best
Sylwia

W dniu 17.01.2023 19:47, pluto via Wien napisał(a):
> Dear Prof. Blaha, dear All,
> 
> I tried x lapw2 -alm (instead of x lapw2 -band -qtl). For me this
> works if I set TEMP in case.in2 (with TETRA and GAUSS I am getting an
> error when running x lapw2 -alm, but it might be some problem with my
> WIEN2k compilation on iMac - I will soon recompile on a new Linux
> machine.)
> 
> Anyway, this produces case.almblm file. I paste the beginning of the
> file below (this is some simple test Ag bulk calculation).
> 
> Is there some documentation of this case.almblm file? To me it seems
> the first column is l and the second column is m. The third column
> seems to be just the index.
> 
> Then there are 10 columns, grouped in pairs (so 5 pairs in total).
> Are those real and imaginary coefficients of the wavefunctions? I
> would expect one complex number per orbital per eigenvalue per
> k-point, why is there 5 of them?
> 
> I understand that it goes beyond the routine use of the lapw2, but
> perhaps you have simple answers...
> 
> I there a way to limit the case.almblm to inlcude only s,p,d, and f 
> orbitals?
> 
> Best,
> Lukasz
> 
> 
> 
> 
>   K-POINT:  1.0000000000  0.5000000000  0.0000000000   112  12 W
>            1           1           8  jatom,nemin,nemax
>            1   ATOM
>            1   1.8018018018018018E-002  NUM, weight
>    0   0   1  2.60221268E-16  0.00000000E+00   -5.40303983E-16
> 0.00000000E+00    0.00000000E+00  0.00000000E+00 0.00000000E+00
> 0.00000000E+00    0.00000000E+00  0.00000000E+00
>    1  -1   2  2.86916281E-16 -4.69385598E-03   -2.00999914E-15
> 1.39370083E-02    0.00000000E+00  0.00000000E+00    3.39480612E-14
> -6.74796430E-01    0.00000000E+00  0.00000000E+00
>    1   0   3 -0.00000000E+00 -2.00964551E-03    0.00000000E+00
> 5.96704418E-03    0.00000000E+00  0.00000000E+00   -0.00000000E+00
> -2.88909932E-01    0.00000000E+00  0.00000000E+00
>    1   1   4  2.86916281E-16  4.69385598E-03   -2.00999914E-15
> -1.39370083E-02    0.00000000E+00  0.00000000E+00 3.39480612E-14
> 6.74796430E-01    0.00000000E+00  0.00000000E+00
>    2  -2   5 -2.42907691E-16  2.49342676E-03   -1.73032916E-16
> -5.78839244E-03   -0.00000000E+00  0.00000000E+00 0.00000000E+00
> 0.00000000E+00    0.00000000E+00  0.00000000E+00
>    2  -1   6  1.82264517E-16 -7.54868519E-04   -4.65058419E-17
> 1.75239766E-03   -0.00000000E+00  0.00000000E+00 0.00000000E+00
> 0.00000000E+00    0.00000000E+00  0.00000000E+00
>    2   0   7 -4.15664411E-16  0.00000000E+00    2.83273479E-16
> -0.00000000E+00   -0.00000000E+00  0.00000000E+00 0.00000000E+00
> 0.00000000E+00    0.00000000E+00  0.00000000E+00
>    2   1   8 -1.82264517E-16 -7.54868519E-04    4.65058419E-17
> 1.75239766E-03   -0.00000000E+00  0.00000000E+00 0.00000000E+00
> 0.00000000E+00    0.00000000E+00  0.00000000E+00
>    2   2   9 -2.42907691E-16 -2.49342676E-03   -1.73032916E-16
> 5.78839244E-03   -0.00000000E+00  0.00000000E+00 0.00000000E+00
> 0.00000000E+00    0.00000000E+00  0.00000000E+00
>    3  -3  10 -5.25533553E-18 -5.74114831E-04   -3.70079029E-16
> 2.64701447E-03    0.00000000E+00  0.00000000E+00 0.00000000E+00
> 0.00000000E+00    0.00000000E+00  0.00000000E+00
>    3  -2  11  1.14832148E-16 -7.09955076E-04    5.94043515E-16
> 2.38542576E-03    0.00000000E+00  0.00000000E+00 0.00000000E+00
> 0.00000000E+00    0.00000000E+00  0.00000000E+00
>    3  -1  12  1.09946596E-16 -2.52160001E-03    1.69024006E-15
> 7.91632710E-03    0.00000000E+00  0.00000000E+00 0.00000000E+00
> 0.00000000E+00    0.00000000E+00  0.00000000E+00
>    3   0  13  0.00000000E+00  4.66796968E-04    0.00000000E+00
> -1.17957558E-03    0.00000000E+00  0.00000000E+00 0.00000000E+00
> 0.00000000E+00    0.00000000E+00  0.00000000E+00
>    3   1  14  1.09946596E-16  2.52160001E-03    1.69024006E-15
> -7.91632710E-03    0.00000000E+00  0.00000000E+00 0.00000000E+00
> 0.00000000E+00    0.00000000E+00  0.00000000E+00
>    3   2  15 -1.14832148E-16 -7.09955076E-04   -5.94043515E-16
> 2.38542576E-03    0.00000000E+00  0.00000000E+00 0.00000000E+00
> 0.00000000E+00    0.00000000E+00  0.00000000E+00
>    3   3  16 -5.25533553E-18  5.74114831E-04   -3.70079029E-16
> -2.64701447E-03    0.00000000E+00  0.00000000E+00 0.00000000E+00
> 0.00000000E+00    0.00000000E+00  0.00000000E+00
>    4  -4  17  4.94473493E-17  8.06437880E-04   -9.23437474E-16
> -2.37542253E-03    0.00000000E+00  0.00000000E+00 0.00000000E+00
> 0.00000000E+00    0.00000000E+00  0.00000000E+00
>    4  -3  18  4.68841179E-17 -2.84229742E-04    8.36550189E-17
> 1.08576915E-03    0.00000000E+00  0.00000000E+00 0.00000000E+00
> 0.00000000E+00    0.00000000E+00  0.00000000E+00
> 
> --
> PD Dr. Lukasz Plucinski
> Group Leader, FZJ PGI-6
> https://electronic-structure.fz-juelich.de/
> Phone: +49 2461 61 6684
> (sent from 9600K)
> 
> 
> --
> This email has been checked for viruses by Avast antivirus software.
> www.avast.com
> 
> 
> 
> 
> 
> 
> On 17/01/2023 11:13, Peter Blaha wrote:
>> a) Yes it is possible to use a "different" local rotation matrix 
>> (AFTER the SCF cycle, and just for the analysis). This way you get the 
>> A_lm,... in this frame.
>> 
>> b) Be aware, that this works only inside spheres, so matrix elements 
>> calculated only from contributions inside spheres will be incomplete 
>> (the LAPW-basis is NOT a LCAO-basis set !!!), though when interested 
>> in localized 3d (4f) electrons it could be a good approximation.
>> 
>> c) Be aware that what you get from qtl are "symmetrized" partial 
>> charges, i.e. the qtl's are averaged over the equivalent k-points in 
>> the full BZ. Note that the A_lm(k=100) are in general different from 
>> A_lm(k=010), even in a tetragonal symmetry, where we usually have only 
>> k=100 in the mesh, but not k=010.
>> 
>> So you probably have to calculate a full k-mesh and sum externally 
>> over the equivalent k-points.
>> 
>> 
>>> Thank you for the quick answer.
>>> 
>>> I am thinking more of a circular dichroism in photoemission, 
>>> intuitive approximate orbital-resolved description in some simple 
>>> cases. For this one needs the quantization axis (the z-axis) along 
>>> the incoming light (this is possible in QTL, as we discussed in 
>>> previous emails) and the phases of the coefficients (which, it seems, 
>>> are not printed-out by QTL).
>>> 
>>> I will look into -alm option, thank you for letting me know this 
>>> option. As I understand, lapw2 projects orbitals only according to 
>>> the coordinate system defined by case.struct file. So I would need to 
>>> rotate the coordinate frame to get the new z-axis along the 
>>> experimental light direction (I think might be tedious but quite 
>>> elementary, I think this is what QTL does).
>>> 
>>> Best,
>>> Lukasz
>>> 
>>> 
>>> 
>>> On 2023-01-16 18:38, Peter Blaha wrote:
>>>> Hi,
>>>> In lapw2 there is an input option ALM (use   x lapw2 -alm), which
>>>> would write the A_lm, B_lm, as well as the radial wf. into a file.
>>>> 
>>>> optical matrix elements: They are calculated anyway in optics.
>>>> 
>>>> Regards
>>>> 
>>>> Am 16.01.2023 um 17:13 schrieb pluto via Wien:
>>>>> Dear Prof Blaha, dear All,
>>>>> 
>>>>> I think QTL provides squared wave function coefficients, which are 
>>>>> real numbers. Can we get the complex coefficients, before squaring? 
>>>>> The phase might matter in some properties, such as optical matrix 
>>>>> elements.
>>>>> 
>>>>> I explain in more detail. We can assume some Psi = A|s> + B|p>. 
>>>>> Using QTL we will get |A|^2 and |B|^2, and we can plot these to 
>>>>> e.g. get the "fat bands", i.e. the orbital character of the bands. 
>>>>> But in general A and B are complex numbers, can we output them 
>>>>> before they are squared?
>>>>> 
>>>>> Best,
>>>>> Lukasz
>>>>> 
>>>>> 
>>>>> 
>>>>> 
>>>>> 
>>>>> 
>>>>> On 22/12/2022 18:12, Peter Blaha wrote:
>>>>>> Subject:
>>>>>> Re: [Wien] QTL quantization axis for Y_lm orbitals
>>>>>> From:
>>>>>> Peter Blaha <peter.blaha at tuwien.ac.at>
>>>>>> Date:
>>>>>> 22/12/2022, 18:12
>>>>>> To:
>>>>>> wien at zeus.theochem.tuwien.ac.at
>>>>>> 
>>>>>> Hi,
>>>>>> In your example with (1. 0. 0.) it means that what is plotted in 
>>>>>> the partial charges (or partial DOS) as pz, points into the 
>>>>>> crystallographic x-axis (I guess it interchanges px and pz). I'm 
>>>>>> not sure if such a rotation would ever be necessary.
>>>>>> 
>>>>>> In your input file you have (1. 1. 1.), which means that pz will 
>>>>>> point into the 111 direction of the crystal.  This could be a real 
>>>>>> and meaningful choice.
>>>>>> 
>>>>>> Such lroc make sense to exploit "approximate" symmetries of eg. of 
>>>>>> a distorted (and tilted) octahedron, where you want the z-axis to 
>>>>>> be in the shortest Me-O direction.....
>>>>>> 
>>>>>> > PS: where can I find the "QTL - technical report by P. Novak"? I don't
>>>>>> > see it on WIEN2k website.
>>>>>> 
>>>>>> This pdf file is in SRC_qtl.
>>>>>> 
>>>>>> Regards
>>>>>> Peter Blaha
>>>>>> 
>>>>>> Am 22.12.2022 um 17:52 schrieb pluto via Wien:
>>>>>>> Dear All,
>>>>>>> 
>>>>>>> I would like to calculate orbital projections for the Y_lm basis 
>>>>>>> (spherical harmonics) along some generic quantization axis using 
>>>>>>> QTL program.
>>>>>>> 
>>>>>>> Below I paste an exanple case.inq input file from the manual 
>>>>>>> (page 206). When "loro" is set to 1 one can set a "new axis z".
>>>>>>> 
>>>>>>> Is that axis the new quantization axis for the Y_lm orbitals? I 
>>>>>>> just want to make sure.
>>>>>>> 
>>>>>>> This would mean that if I set the "new axis" to 1. 0. 0., I will 
>>>>>>> have the basis of |pz+ipy>, |px>, and |pz-ipy>. It that correct?
>>>>>>> 
>>>>>>> Best,
>>>>>>> Lukasz
>>>>>>> 
>>>>>>> PS: where can I find the "QTL - technical report by P. Novak"? I 
>>>>>>> don't see it on WIEN2k website.
>>>>>>> 
>>>>>>> 
>>>>>>> 
>>>>>>> ------------------ top of file: case.inq --------------------
>>>>>>> -7. 2. Emin Emax
>>>>>>> 2 number of selected atoms
>>>>>>> 1 2 0 0 iatom1 qsplit1 symmetrize loro
>>>>>>> 2 1 2 nL1 p d
>>>>>>> 3 3 1 1 iatom2 qsplit2 symmetrize loro
>>>>>>> 4 0 1 2 3 nL2 s p d f
>>>>>>> 1. 1. 1. new axis z
>>>>>>> ------------------- bottom of file ------------------------
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