TDDFT+LRC

[samaneh]

Dear Developers,

Would you please tell me about the runlevel to calculate
TDDFT+dynamical LRC??
According to the tutorial for solid LiF
"yambo -o c -k lrc" is for the static LRC
but how about dynamic one??

Best regards
S. Ataei

[Daniele Varsano]

Dear Samaneh,
yes, "yambo -o c -k lrc" is for the static LRC.
The dynamic version is the so called nanoquanta kernel see e.g.:
Phys. Rev. Lett., 91, 256402 (2003).
Phys. Rev. Lett. 101, 133002 (2008)

which is quite cumbersome and essentially relies on the screening of BSE.
Unfortunately it is not in the GPL release, anyway at the same computational cost you can perform BSE calculations, having results of the same quality.
Best,

Daniele

[samaneh]

Dear Daniele,

Thanks for your quick reply.
yes I have read these papers
But I also read the paper PRB84, 085145 (2011)
which they used YAMBO code to do dynamical TDDFT!!!
they say that BSE is more computationally demanding
and I found that it might be
feasible to use yambo code to do dynamical TDDFT!!!

All the best
S. Ataei

[Daniele Varsano]

Dear Samaneh,
you are perfectly right!
You can add the dynamical dependence by setting the parameter beta (see paper of S. Botti).
In order to activate it you need to set:

Code: Select all

LRC_beta

it appears in the input file when you include more verbosity in the response function:

Code: Select all

yambo -o c -k lrc -V resp

Sorry for the late post, I was not aware of that.
Best,

Daniele

[samaneh]

Dear Daniele,

Thank you.
I will check it.

Best regards
Samaneh

[samaneh]

Dear Daniele,
first I run yambo -g n -p p and yambo
then I tried "yambo -o c -k lrc -V resp"
or even "yambo -o c -k lrc -V all"
but there is no any LRC_beta or LRC_alpha!!!
here is the generated input file:
#
# GPL Version 3.4.1 Revision 3187
# http://www.yambo-code.org
#
optics # [R OPT] Optics
chi # [R CHI] Dyson equation for Chi.
FFTGvecs= 999 RL # [FFT] Plane-waves
NonPDirs= "none" # [X/BSS] Non periodic chartesian directions (X,Y,Z,XY...)
Chimod= "LRC" # [X] IP/Hartree/ALDA/LRC/BSfxc
NGsBlkXd= 1 RL # [Xd] Response block size
% QpntsRXd
1 | 39 | # [Xd] Transferred momenta
%
% BndsRnXd
1 | 200 | # [Xd] Polarization function bands
%
GrFnTpXd= "t" # [Xd] Green`s function t/c/r/a
% EnRngeXd
0.00000 | 10.00000 | eV # [Xd] Energy range
%
% DmRngeXd
0.10000 | 0.10000 | eV # [Xd] Damping range
%
DmERefXd= 0.000000 eV # [Xd] Damping reference energy
CGrdSpXd= 100.0000 # [Xd] [o/o] Coarse grid controller
ETStpsXd= 100 # [Xd] Total Energy steps
EMStpsXd= 100.0000 # [Xd] [o/o] Memory Energy steps
DrudeWXd= ( 0.00 , 0.00 ) eV # [Xd] Drude plasmon
% EhEngyXd
-1.000000 |-1.000000 | eV # [Xd] Electron-hole energy range
%
% LongDrXd
1.000000 | 0.000000 | 0.000000 | # [Xd] [cc] Electric Field
%
% Qdirection
0.00 | 0.00 | 0.00 | # [Xd] Transferred momentum direction (iku)
%
QShiftOrder= 1 # [Xd] Pick-up the (QShiftOrder)th q+G vector

I would be thankful if you help me with this problem!!!

Best regards
Samaneh

[Daniele Varsano]

Dear Samaneh,
this is very odd, I cannot reproduce your problem.
Try to start by scratch: remove your input file (or even also your previous ndb.* databases). Next run the setup and

Code: Select all

yambo -o c -k lrc -V resp

You should have something like this:

optics # [R OPT] Optics
chi # [R CHI] Dyson equation for Chi.
tddft # [R K] Use TDDFT kernel
NonPDirs= "none" # [X/BSS] Non periodic chartesian directions (X,Y,Z,XY...)
Chimod= "LRC" # [X] IP/Hartree/ALDA/LRC/BSfxc
LRC_alpha= 0.000000 # [TDDFT] LRC alpha factor
LRC_beta= 0.000000 # [TDDFT] LRC beta factor
NGsBlkXd= 1 RL # [Xd] Response block size
....

Best,

Daniele

[samaneh]

Dear Daniele,
I did :
mpirun p2y -S -N
mpirun yambo -i -V RL
mpirun yambo
mpirun yambo -o c -k lrc -V resp
from scratch
but again I got the same!!!!

optics # [R OPT] Optics
chi # [R CHI] Dyson equation for Chi.
NonPDirs= "none" # [X/BSS] Non periodic chartesian directions (X,Y,Z,XY...)
Chimod= "LRC" # [X] IP/Hartree/ALDA/LRC/BSfxc
NGsBlkXd= 1 RL # [Xd] Response block size
% QpntsRXd
1 | 39 | # [Xd] Transferred momenta
%
% BndsRnXd
1 | 200 | # [Xd] Polarization function bands
%
GrFnTpXd= "t" # [Xd] Green`s function t/c/r/a
% EnRngeXd
0.00000 | 10.00000 | eV # [Xd] Energy range
%
% DmRngeXd
0.10000 | 0.10000 | eV # [Xd] Damping range
%
DmERefXd= 0.000000 eV # [Xd] Damping reference energy
CGrdSpXd= 100.0000 # [Xd] [o/o] Coarse grid controller
ETStpsXd= 100 # [Xd] Total Energy steps
EMStpsXd= 100.0000 # [Xd] [o/o] Memory Energy steps
DrudeWXd= ( 0.00 , 0.00 ) eV # [Xd] Drude plasmon
% EhEngyXd
-1.000000 |-1.000000 | eV # [Xd] Electron-hole energy range
%
% LongDrXd
1.000000 | 0.000000 | 0.000000 | # [Xd] [cc] Electric Field
%
% Qdirection
0.00 | 0.00 | 0.00 | # [Xd] Transferred momentum direction (iku)
%
QShiftOrder= 1 # [Xd] Pick-up the (QShiftOrder)th q+G vector

[Daniele Varsano]

Dear Samaneh,
No idea on what is going on as I cannot reproduce it!

Anyway:
> yambo -o c -k lrc -V resp
why mpirun ????

What I can suggest you:

1) Check if you are using the last version (svn update), but I think so.
2) Add by hand the input variables:

Code: Select all

tddft # [R K] Use TDDFT kernel
LRC_alpha= xx # [TDDFT] LRC alpha factor
LRC_beta= xx # [TDDFT] LRC beta factor

3) Switch to yambo devel 4.0.2

Best,
Daniele