[Wien] 1) ENE warning during SCF loop for core-hole calculation and 2) temperature effects

[van der Veen, Renske]

Dear WIEN2k users,

With the aim of calculating the ELNES spectrum of graphite, I am running SCF calculations with a core-hole inside a 3x3x1 supercell. I adopt the excited-atom approach for the core-hole, i.e. I remove one electron from the 1s orbital of the first atom in the list of inequivalent supercell atoms (.inc file), and I add it as a smeared-out background charge (+1.0) in the .inm file.

I have some questions in order to reassure myself that I am on the right track:

****

(1) I noticed that during SCF loop, there is a WARNING written about the total energy ENE:

:ENE  : *WARNING** TOTAL ENERGY IN Ry =        -2705.52776014

In addition to a warning about the charging of the cell:

:WARN  :        CHARGED CELL with   1.000

I assume this is due to the addition of the core-hole. Is it safe to "ignore" this warning? It seems to me that the total energy value is very large… (negatively)

I also noticed that the first two iterations of the SCF loop display 0 values for the ETEST and CTEST parameters in the STDOUT file. On the 3rd iteration, the two parameters get sensible values. The full convergence (0.0001 cc) is reached after 18 iterations. What is the reason for the initial 0 values for ETEST and CTEST?

****

(2) I was wondering: is it possible to include temperature effects in the ELNES calculation? E.g. Comparing the simulated graphite ELNES spectrum at 300 K with the one at 1000 K. Except for the obvious thermal expansion of the lattice (which I could estimate from the thermal expansion coefficients), I am wondering about the effect of disordering of the atom positions on the spectrum.

Thanks in advance for your help!

Best regards,
Renske

P.S. I am using version WIEN2k_13.1 (Release 17/6/2013) compiled with ifort.

--

Dr. Renske M. van der Veen
Deutsches Elektronen Synchrotron (DESY)
Notkestraße 85, 22607 Hamburg
and
Max Planck Institute for Biophysical Chemistry
Am Faßberg 11, 37077 Göttingen
Germany

Tel (work): 0551 201 1265
Tel (mobile): 0176 315 05894
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