Hi, Could someone please tell what is the unit of dynamical matrix elements'. I have to do some post processing from the dynamical matrices and therefore I want to know the proper units of the elements.
Thank you, Shubham ----- Original Message ----- From: "Shubham Patel" <spatel...@iitkgp.ac.in> To: "Quantum ESPRESSO users Forum" <users@lists.quantum-espresso.org> Sent: Wednesday, April 9, 2025 8:09:58 AM Subject: Re: [QE-users] unit mismatch between PH generated frequencies and manually generated eigenvalues Dear Kazume NISHIDATE, Thank you very much for your prompt reply. This is indeed correct what you observed. However, when I divide the y scale of right hand side figure with 0.005 it should return the left figure but it does not. Attaching the modified figure in the right most (dividing with 0.005). Am I missing something? Thank you, Shubham ----- Original Message ----- From: "Kazume NISHIDATE" <nisid...@iwate-u.ac.jp> To: "Quantum ESPRESSO users Forum" <users@lists.quantum-espresso.org> Sent: Wednesday, April 9, 2025 1:54:59 AM Subject: Re: [QE-users] unit mismatch between PH generated frequencies and manually generated eigenvalues Dear Shubham, I’m not an expert on the phonon calculation. But it may be in a wavelength unit. The bottom of the curve in the left-hand graph is around 25 meV. 25 meV = 0.025 eV 0.025 eV is around 50 micro m (wavelength). https://sherwingroup.itst.ucsb.edu/internal/unit-conversion/ = 50 x 10^(-6) m = 50 x 10^(-6) x 100 cm = 50 x 10^(-4) cm = 5 x 10^(-3) cm = 0.005 cm It is around the bottom of the curve in the right-hand graph. > 2025/04/09 0:03、Shubham Patel <spatel...@iitkgp.ac.in>のメール: > > Dear developers and users, > > I am trying to calculate the frequencies (freqs) using Quantum Espresso > PHonon calculations as well as using dynamical matrices generated using > matdyn.x. I find that there is a unit mismatch in the freqs which gives rise > to a magnitude difference. In the first case, I calculate phonon band > structure using matdyn.x --> plotband.x. While in the second case I generate > dynamical matrices using matdyn.x and then diagonalize the matrices along the > kpath and generated exactly same band dispersion except the magnitude on the > y-axis (frequency range). Could anyone please tell what is this factor which > brings the magnitude mismatch? I am also attaching a figure to compare. > > Thank you very much for any help. > > Sincerely, > Shubham<phdos_AZX_mimatch.pdf>__________________________________________________ 西館数芽 Kazume NISHIDATE Ph.D Department of Systems Innovation Engineering, Graduate School of Science and Engineering, Iwate University 4-3-5 Ueda, Morioka, Iwate, 020-8551 JAPAN Phone:+81-19-621-6391 kazume.nishid...@gmail.com, nisid...@iwate-u.ac.jp https://sites.google.com/site/nisidatelab/ _______________________________________________________________________________ The Quantum ESPRESSO Foundation stands in solidarity with all civilians worldwide who are victims of terrorism, military aggression, and indiscriminate warfare. -------------------------------------------------------------------------------- Quantum ESPRESSO is supported by MaX (www.max-centre.eu) users mailing list users@lists.quantum-espresso.org https://lists.quantum-espresso.org/mailman/listinfo/users _______________________________________________________________________________ The Quantum ESPRESSO Foundation stands in solidarity with all civilians worldwide who are victims of terrorism, military aggression, and indiscriminate warfare. -------------------------------------------------------------------------------- Quantum ESPRESSO is supported by MaX (www.max-centre.eu) users mailing list users@lists.quantum-espresso.org https://lists.quantum-espresso.org/mailman/listinfo/users
