[Pw_forum] TDDFT approach for periodic system

I completely agree, one should focus on excitonic characters in these kind of discussions For archival purposes and for not risking being esoteric to the newcomers to the field, I would like to mention some commonly used references regarding the tests performed in the theoretical chemistry literat

[Pw_forum] TDDFT approach for periodic system

Just a couple of further comments. 1) The ability (or lack thereof) of (adiabatic) tddft to properly describe optical excitations in extended systems does not depend on the code's ability to sample the whole BZ using special k-points. The current version of the tddfpt code distributed with QE is

[Pw_forum] TDDFT approach for periodic system

A further addition and good reading why adding k-points to TDDFT might not be that straightforward: THE JOURNAL OF CHEMICAL PHYSICS 129, 034101 "Why are time-dependent density functional theory excitations in solids equal to band structure energy gaps for semilocal functionals, and how does nonloc

[Pw_forum] TDDFT approach for periodic system

Dear All, The current implementation of TDDFPT in Q-E is intended for "standalone" systems (i.e. non bulk, solvated or encapsulated in dielectric systems are ok). You will see confinement effects in lower dimensional systems (including 1D and 2D systems) in the non-extended dimensionality(-ies) sav

[Pw_forum] TDDFT approach for periodic system

Dear all I did not say that TDDFPT does not work with periodic system, but you cannot have a realistic absorption spectra of a slab (or bulk crystal) if you sample the Brillouin zone by using Gamma only... TDDFPT works fine with finite systems, i.e., which do not show a (strong) k dependence of

[Pw_forum] TDDFT approach for periodic system

Dear Priya, Though I have never tried, it should work with periodic systems if you sample the Brillouin zone only with the gamma point. Keep in mind that the usual adiabatic approximations with (semi)local functionals might not work very well for calculating the absorption of periodic systems. Ma

[Pw_forum] TDDFT approach for periodic system

Thanks Marton, its working. On Tue, Apr 19, 2011 at 5:40 PM, Marci wrote: > Dear Priya, > > Though I have never tried, it should work with periodic systems if you > sample the Brillouin zone only with the gamma point. Keep in mind that > the usual adiabatic approximations with (semi)local funct

[Pw_forum] TDDFT approach for periodic system

Thanks Duy, but the link does not give sufficient information. However, I found a discussion on forum's archive itself where Giuseppe Mattioli has mentioned that TDDPFT does not work for periodic systems* :-( *Dr Priya Johari. Brown University, Providence, RI - 02906. USA * * On Tue, Apr 19, 2011

[Pw_forum] TDDFT approach for periodic system

If you do a little homework (such as googling keyword TD-DFPT), you'll find this link http://qe-forge.org/projects/tddfpt/ I have not read it carefully but I guess it contains some useful information. -- Duy Le PhD Student Department of Physics Univer

[Pw_forum] TDDFT approach for periodic system

Dear Developers, I was wondering if recently implemented TD-DFPT tool in espresso-4.3 can be used for calculating absorption spectrum of period systems (slab or so)? Thanks in advance. Regards, Dr Priya Johari. Brown University, Providence, RI - 02906. USA -- next part --