Dear Chiara Thanks for your reply. Yes I was planning to compute dynamical susceptibility and Nesting functions to sort out the issue. Professor Kawamura suggested me that I can compute nesting functions within Fermi surfer package itself. I will be exploring the new features. Thanks for your suggestions and useful references. Regards Ramesh Asst Professor GITAM Vizag India
On Mon, Aug 21, 2023, 4:19 AM Chiara Cignarella via users < users@lists.quantum-espresso.org> wrote: > Dear Kumar, > > In order to make sure you have a nesting of the Fermi surface you should > plot the nesting function (the double deltas function); the points where > you see the peaks are the nesting points of the Fermi surface. > > The phonon softening in the phonon dispersion that you observe should be > a Kohn anomaly. It is likely to be related to the Fermi nesting, but not > straightforward. > > You can have a look at some of the literature about, like for example > ”Johannes and Main PRB 77, 2008”, "Zhu X. Et al PNAS 2015", or more > standard books like Khomskii “Basic aspects of quantum theory of solids”, > Chapter 9 and 11. > > Best > Chiara Cignarella > > PhD student > EPFL > > > > On 19 Aug 2023, at 18:13, ukawamura u <mkawam...@ds.itc.u-tokyo.ac.jp> > wrote: > > > > Dear Dr.Kamadurai > > > > Maybe you are using FermiSurfer. > > I added function to compute two kinds of nesting function namely > > double-delta and Lindhard-type: > > > https://mitsuaki1987.github.io/fermisurfer/en/_build/html/ops.html#nesting-function > > This version was released today. > > https://github.com/mitsuaki1987/fermisurfer/releases/tag/2.4.0 > > > > Best regards, > > Mitsuaki Kawamura > > > > Mitsuaki Kawamura > > Data Science Research Division, Information Technology Center, The > > University of Tokyo > > e-mail: mkawam...@ds.itc.u-tokyo.ac.jp > > > > 2023年8月16日(水) 15:06 Ramesh Kumar Kamadurai via users > > <users@lists.quantum-espresso.org>: > >> > >> Dear All > >> I am writing to get some clarification about the nesting of the Fermi > surface. Since the FS geometry looks complex, I need help understanding it > correctly. Sorry for asking non-QE-related question. I have calculated the > Fermi surface for a conventional cell and projected it onto the primitive > cell. When examining a slice along the 110 direction, I noticed two > parallel lines at the boundary's edge. Further in the phonon calculation, I > observed phonon softening (imaginary frequency) at the same M point. Is > there a connection between this stitching of surfaces on the Fermi surface > and the observed phonon softening, and finally, is there a nesting? I am > attaching the relevant pictures. Thanks in advance for your suggestion. > >> > >> Best regards, > >> > >> K. Ramesh Kumar > >> > >> Assistant Professor > >> > >> Gandhi Institute of Technology and Management, > >> > >> Phone: +91 9895637981, +1 6782419790 > >> > >> Email: kraames...@gmail.com rkama...@gitam.edu > >> > >> _______________________________________________ > >> 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 users@lists.quantum-espresso.org > >> https://lists.quantum-espresso.org/mailman/listinfo/users > > _______________________________________________ > > 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 users@lists.quantum-espresso.org > > https://lists.quantum-espresso.org/mailman/listinfo/users > > _______________________________________________ > 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 users@lists.quantum-espresso.org > https://lists.quantum-espresso.org/mailman/listinfo/users
_______________________________________________ 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 users@lists.quantum-espresso.org https://lists.quantum-espresso.org/mailman/listinfo/users
