Hi Dr. Paulatto, Thank you so much for your fruitful suggestions. I will do that in QE accordingly. Though I have very limited knowledge in QE, your explanation is understandable. Thank you so much.
Best Md Jahid On Fri, Jan 12, 2024 at 10:26 AM Lorenzo Paulatto <[email protected]> wrote: > p.s. Have a look at > https://journals.aps.org/prb/pdf/10.1103/PhysRevB.94.075125 where the > temperature dependent spectrum is in fact computed from the RMS > > hth > On 1/11/24 04:46, Md. Jahid Hasan Sagor wrote: > > Hi Dr. Paulatto, > > Thank you so much for your comments. > > Actually, The paper ( https://doi.org/10.1103/PhysRevB.77.125218 ) > extracted the temperature of each configuration from the mean square > displacement per atom of the configuration (GaAs). In the harmonic > approximation, they determined the relationship between mean square > displacement and temperature T from the phonon density of states of bulk > GaAs calculated by Giannozzi et al. The equation as follows: > > [image: image.png] > Here is the figure they generated > [image: image.png] > > > So, now If I can find out the RMS of GaAs using CPMD, I will try to > observe the corresponding configuration of GaAs atoms. Finally, the atomic > positions will be the input of Quantum Espresso pw.x etc ( I mean normally > how do we calculate dielectric constant in QE). > > Can I use it ( https://anharmonic.github.io/thermal2/#d3_r2qx-code) for > the same purpose? > > Best > Hasan > > On Wed, Jan 10, 2024 at 3:13 PM Lorenzo Paulatto <[email protected]> > wrote: > >> I would guess that you calculate the static dielectric constant at the >> temperature-dependent volume (experimental, or quasi-harmonic) and you are >> 90% of the way there. Do you have a specific reason to believe that it >> would be proportional to the RMS ? >> >> Btw, the code d3_r2q.x included with the "anharmonic" package can compute >> the RMS from an inexpensive phonon calculation, maybe have a look at it >> before doing a large supercell MD. >> >> https://anharmonic.github.io/thermal2/#d3_r2qx-code >> cheers >> >> On 10/01/2024 19:35, Md. Jahid Hasan Sagor wrote: >> >> Actually, I have to calculate Dielectric constant for GaAs for different >> temperatures (not 0 k). To do that, I need to extract atomic positions for >> different RMS using CPMD. If anyone know someone/ or give some guidelines, >> it would be great help for me. >> >> Thank you. >> >> On Tue, Jan 9, 2024, 2:09 PM Md. Jahid Hasan Sagor <[email protected]> >> wrote: >> >>> Dear QE community, >>> >>> I want to calculate the mean square displacement of GaAs using CPMD. >>> From the mean square displacement, I want to extract the configuration of >>> atoms (e.g atomic position of Ga and As). Could anyone please give me some >>> guidelines on how I can perform it? Should I use only the cp.x package or >>> by other means? Your time and suggestions would be a great help for me. >>> >>> Best Regards >>> Md Jahid Hasan >>> PhD Student, Mechanical Engineering >>> University of Maine >>> >> >> _______________________________________________ >> The Quantum ESPRESSO community stands by the Ukrainian >> people and expresses its concerns about the devastating >> effects that the Russian military offensive has on their >> country and on the free and peaceful scientific, cultural, >> and economic cooperation amongst peoples >> _______________________________________________ >> Quantum ESPRESSO is supported by MaX (www.max-centre.eu) >> users mailing list >> [email protected]https://lists.quantum-espresso.org/mailman/listinfo/users >> >> -- >> Dr. Lorenzo Paulatto >> IdR @ IMPMC - CNRS UMR 7590 & Sorbonne Université >> phone: +33 (0)1 442 79822 / skype: paulatz >> http://www.impmc.upmc.fr/~paulatto/ - https://anharmonic.github.io/ >> 23-24/423 B115, 4 place Jussieu 75252 Paris CX 05 >> _______________________________________________ >> The Quantum ESPRESSO community stands by the Ukrainian >> people and expresses its concerns about the devastating >> effects that the Russian military offensive has on their >> country and on the free and peaceful scientific, cultural, >> and economic cooperation amongst peoples >> _______________________________________________ >> Quantum ESPRESSO is supported by MaX (www.max-centre.eu) >> users mailing list [email protected] >> https://lists.quantum-espresso.org/mailman/listinfo/users > > -- > Dr. Lorenzo Paulatto > IdR @ IMPMC - CNRS UMR 7590 & Sorbonne Université > phone: +33 (0)1 442 79822 / skype: paulatz > http://www.impmc.upmc.fr/~paulatto/ - https://anharmonic.github.io/ > 23-24/423 B115, 4 place Jussieu 75252 Paris CX 05 >
_______________________________________________ The Quantum ESPRESSO community stands by the Ukrainian people and expresses its concerns about the devastating effects that the Russian military offensive has on their country and on the free and peaceful scientific, cultural, and economic cooperation amongst peoples _______________________________________________ Quantum ESPRESSO is supported by MaX (www.max-centre.eu) users mailing list [email protected] https://lists.quantum-espresso.org/mailman/listinfo/users
