Step 1: Install the DFT program; learn how to do scf calculations with
unit cells, then supercells (with WIEN2k) [1].
- Phonon calculations use primitive cells [2].
Step 2: Research available phonon software (for WIEN2k) and decide which
one you will use.
- For
Sir with due respect, i am a new commer in the feild of computational
methods, but sir i need a procedure of steps to calculate phonon. If you
can provide me or give me any lead i will be very thankful to you and it
will be your most kindness. (PLEASE SIR I NEED THE PROCEDURE PLZ)
Respected Prof. Blaha ,
Thank you so much for your reply.
I did it because I read Kevin Jorissen's mail:
http://zeus.theochem.tuwien.ac.at/pipermail/wien/2006-August/007602.html
I probably never did the right thing. I'll do what you suggest.
With kind regards.
Respected Prof. Marks ,
Thank you so much for your reply.
'One way to minimize the effect is to tilt off the zone axis to a
pseudo-kinematical condition', does this mean I need to change the angle a
little bit? For example, change from
ORIENTATION SENSITIVE
0.0 0.0 0.0
to
ORIENTATION
The only difference is that with -min the run** code will switch from MSR1
to MSR1a, minimize, then switch back to MSR1 when the forces are small and
fully converge the density. Depending on what (old ?) version of run** you
are using it may not do this switching for you.
The later run** also has
Dear Prof. Laurence Marks
Thank you very much for your answer
*For the case of my calculations, I want to optimize the internal
parameters of an atom of a **chalcopyrite**, **usually I used MSR1a without
-min (old WIEN2k versions) :*
*runsp -fc 1*
*save xxx*
*i change MSR1 to MSR1a *
*runsp -fc
There is in my opinion no "right" method. The question is what are you
trying to do?
Case 1: A structure with fixed positions or a problem where you "don't
care" about minor forces, e.g. calculating a simple bulk structure. Then
just "runsp -cc 0.0001 -ec 0.0001" is fine. (I prefer to use -cc as
Dear Wien2k user;
According to user guide, after a SCF cycle with runsp -fc 1 we continue
with run runsp -min
I want to know which of these two methods is the correct one:
1)
runsp -fc 1
runsp -min
runsp -min -fc 0.5 -ec 0.0001 -cc 0.001
or
2)
runsp -fc 1
runsp -min -fc 0.5 -ec 0.0001 -cc 0.001
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
There are two fundamental issues:
a) How to handle the dynamical diffraction of the swift electrons.
b) How to handle the core hole.
To my knowledge no DFT code handles a) correctly. (Some details are in Chpt
5 of "High-Resolution Transmission Electron Microscopy: and Associated
Techniques" Eds
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
11 matches
Mail list logo
