I do not understand your statement:
> As it is supercell, I calculated every peak of unequivalent O K edge and
> summed them. I'm not sure all the steps I have done are right. The
Of course, only atom 7 has the core hole, the other atoms of the
supercell can contribute to screening. But only the spectrum of atom 7
is meaningful, not that of the other O atoms. So don't sum up anything,
just calculate the spectrum for atom 7.
On 10/15/18 1:53 PM, yfding wrote:
This problem haunts me for nearly a year, and my questions are still
unsolved after consulting a lot of literature and mailing list.
I tried to get Oxygen K edge of the 3*3*3 SrCrO3 supercell.
In my calculations, I first converted the SrCrO3 (space group P4/mmm)
into a SrCrO3 3*3*3 supercell (space group P1) in CrystalMaker, then
transformed the SrCrO3supercell.cif file into SrCrO3supercell.struct
file under the Wien2k case directory, labelled one oxygen atom to make
this atom unique, did initialization, and accepted all the queries from
nn complaints. The initialization parameters were as follows:
Rmt: Sr:2.40 Cr:1.78 O:1.61
potential: GGA of PBE-96
separation energy: -6.0 Ry
RKmax: 7.0
Max L in WF: 10
number of k points in the whole BZ: 5*5*5
number of k points in the irreducible wedge of the BZ: 18
Then I edited SrCrO3.inc and removed one core electron from the 7th
atom, i.e. 1st Oxygen atom 1s state. Next I changed 0.0 to -1.0 in
SrCrO3.inm. Then run SCF in parallel (energy convergence 0.0001 Ry).
Then,
-edited case.innes :
SrCrO3 O K edge
7 (atom)
1, 0 (n, l core)
532 (E-Loss of 1st edge in eV)
200 (energy of the incident electrons in keV)
-5.0 20.0 0.1 (minimum energy, energy step, maximum energy)
0.37 0.75 (collection semiangle, convergence semiangle, both in mrad)
50 1 (NR, NT, defining the integration mesh in the detector plane)
0.7 (spectrometer broadening in eV)
OUTPUT
0 (full output)
DETECTOR POSITION
0.0 0.0 (thetax, thetay)
MODUS
energy (dscs wrt what?)
ORIENTATION SENSITIVE
0.0 0.0 0.0
SELECTION RULE
n (selection rule)
LSELECTION RULE
d
INITIALIZATION
y y (dos and xdos handling)
y y (handling of rotation matrices)
QGRID
U
END
- x lapw1
- x lapw2 -qtl
- x qtl -telnes
- x telnes3
- x broadening
As it is supercell, I calculated every peak of unequivalent O K edge and
summed them. I'm not sure all the steps I have done are right. The
result is different from the TEM EELS experiment (The O K edge EELS
spectra were studied on an JEOL ARM200F Cs-corrected TEM with a FEG and
a Gatan parallel electron-energy-loss spectroscope). The relative
strength and position of the peaks are completely inconsistent.
It's not just this example, but I've had the same problem with all the
other materials. I thought about all the possible reasons, and looked up
lots of literature and mailing lists, but I couldn't get the calculation
results closer to the experiment. I want to know how to obtain ELNES
simulation results consistent with experiments ?
Any comment(s) would be highly appreciated. Thanks in advance!
_______________________________________________
Wien mailing list
Wien@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
--
P.Blaha
--------------------------------------------------------------------------
Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna
Phone: +43-1-58801-165300 FAX: +43-1-58801-165982
Email: bl...@theochem.tuwien.ac.at WIEN2k: http://www.wien2k.at
WWW: http://www.imc.tuwien.ac.at/TC_Blaha
--------------------------------------------------------------------------
_______________________________________________
Wien mailing list
Wien@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