[Wien] [Re-posting] Questions about calculating ELNES specturm with parallel option

[Yi yoo soo]

Dear, all users.

 

I am sorry for the multiple postings. In my previous letter, it seems that
my questions were not clearly presented. More detailed descriptions of the
problem and system specifications are described below. I have been faced
with a problems of calculating ELNES spectrum. 

 

(1)     Checked crystalline system

I've calculated a ELENS spectrum using MgO to check whether Wien2k is
properly compiled on my system. The tests include, 

a)_Single cell MgO without k-point parallelization option, 

b)_single cell MgO with parallel option,

c)_2x2x2 super cell MgO with parallel option, 

and finally d) 2x2x2 super cell without parallel option. 

 

(2)     ELNES calculation procedure

Used structural information: MgO structure with 2x2x2 super cell generated
with x_supercell

Details of setting (case.in* files): I just followed the setting from the
*.pdf files uploaded in web page.

init_lapw (with 1000 k-point, RKmax=6.5)

edit case.in1 (increase the energy maximum values to calculate higher energy
region in TELNES from default to 4.5 eV)

run_lapw -it (use iterative diagonalization, convergence criteria is set to
charge 0.0001)

telnes (for Mg K-edge spectrum, setting edge onset, etc., energy grid from 0
eV to 35.0 eV)

I did not set the broadening variables (just to check the possibility of
calculating spectra)

(almost other variables are used with default values)

 

(3)     Results from test

As test a), we've got the result, consistent with the results shown in the
Wien2K tutorial (of latest conference file).

As test b), we cannot get the desired result. Instead, the ELNES spectrum is
calculated only up to 11 eV (note that we set the energy grid of up to 35
eV, I also changed emax value according in the case.in1 file). 

As test c), it took about 5 days to complete the SCF cycles. It also
produced the ELNES spectrum with only up to 11 eV (almost same as result of
test 'b').

As test d), a single SCF cycle for the run takes almost 10 hours, and thus
so I was forced to quit the job. (I think that it takes too long time to run
single SCF cycle comparing with other commercial code that I tested,
although they are using different approximation methods defining wave
functions.)

 

(4)     Related problems of these results