[QE-users] Calculate phonons only at the interface

[thorgalg]

Dear Christian,
I spend the last two weeks testing this setting (nat_todo=16).
My system contains more than 200 atom and was optimized
until the forces on all the atoms were less than 0.02 eV/A.
Then, I wanted to calculate the zero-point-energy (zpe) correction
for the adsorbed molecule (benzene derivative) using ph.x. Unfortunately,
I obtained a lot of imaginary frequencies (at the beginning of dynamical
matrix in the ph.out file ):
     freq (    1) =     -98.010682 [THz] =   -3269.284435 [cm-1]
     freq (    2) =     -95.651863 [THz] =   -3190.602722 [cm-1]
     freq (    3) =     -72.672472 [THz] =   -2424.092724 [cm-1]
     freq (    4) =     -71.325508 [THz] =   -2379.162841 [cm-1]
     freq (    5) =     -66.443681 [THz] =   -2216.322637 [cm-1]
     freq (    6) =     -63.174512 [THz] =   -2107.274901 [cm-1]
     freq (    7) =     -61.771254 [THz] =   -2060.467247 [cm-1]
     freq (    8) =     -59.520061 [THz] =   -1985.375532 [cm-1]
...
...
Then, when I wanted to calculate the dynamical matrix, the program
(dynmat.x) stuck on attemption the asr calculation.
....
Acoustic Sum Rule: || Z*(ASR) - Z*(orig)|| =    0.000000E+00
The input file for dynmat.x is:
&input
 fildyn = 'benz_surf.dyn'
 asr = 'zero-dim'
/
If this setting will work properly, it would be very helpful for all these QE
users working on the theoretical catalysis.
Best,
Tomasz Krol
Cracow University of Technology
 
W dniu 2019-11-05 17:42:13 użytkownik Hari Paudyal <hpaudya1 at binghamton.edu> napisał:
Hi Christian,
 
nat_todo  can be used to choose the subset of atoms to be used in the linear response calculation. Please have a look if that is under your interest.
 
Best,
Hari Paudyal
SUNY, Binghamton
On Tue, Nov 5, 2019 at 11:26 AM Christian helman <christian.helman at gmail.com> wrote:
Hi
I just calculate an interface between two compounds. No problem and
results are as expected.
however I would like to calculate the phonons at the interface (even
more electron -phonon coupling but let's start with just phonons).
Since my unit cell is huge, my question is :
is there any way to calculate the phonons "only at the interface" by
allowing to move the interface atoms ?? something like "selective
dynamics"
Thanks in advance
--
Dr. Christian Helman
Departamento de Neutrones y Reactores
Centro Atómico Bariloche -CNEA
Ezequiel Bustillos 9,500 Km - CP 8400
San Carlos de Bariloche
Provincia de Rio Negro, Argentina
Tel:++54-294-444-5100 int 5308
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