Hi Xu Huang,
All I know is there is a similar question to this on the forum asked recently: Lorenzo Paulatto answered the following: Hello, in density function perturbation theory, contrary to finite-differenes method, there is no atom displacement: quantum-mechanics perturbation theory is used. See this reference: <<https://outlook.office.com/owa/?realm=leeds.ac.uk&path=/mail/search>http://journals.aps.org/rmp/abstract/10.1103/RevModPhys. 73.515> for details on the method how it is implemented in QE. Tis lecture from Stefano Baroni to get a quick idea: < https:// www.dropbox.com/s/xi06fv6oz07j9du/EUSPec%202016%20%281%29.pdf?dl=0<http://www.dropbox.com/s/xi06fv6oz07j9du/EUSPec%202016%20%281%29.pdf?dl=0>> So there is likely nothing wrong with the axsf file. For your second question however I am not sure how to animate, unless you do it manually using the force vector directions? Regards, Louis ________________________________ From: pw_forum-boun...@pwscf.org <pw_forum-boun...@pwscf.org> on behalf of Huang, Xu <xu-hu...@uiowa.edu> Sent: 27 March 2017 05:40:51 To: pw_forum@pwscf.org Subject: [Pw_forum] Phonon axsf does not move in XCrysden Dear all, I'm using QE-5.2.0 to do the phonon calculation to test some small gas molecules, such as O2, CH4 etc. I got a "dynmat.axsf" for O2 with 6 modes shown below. However, when I type "xcrysden --axsf dynmat.axsf" to visualize the vibrational mode, I can't see any movement when I click the <- and -> arrows back and forth. (I do see the arrows of forces when display them.) Is there anything wrong with this axsf file? Or is there any parameter for the dynmat.x to produce specific axsf to animate a certain mode? Thank you, Xu Huang ----------------------------------------------------- ANIMSTEPS 6 CRYSTAL PRIMVEC 21.167088344 0.000000000 0.000000000 0.000000000 21.167088344 0.000000000 0.000000000 0.000000000 21.167088344 PRIMCOORD 1 2 1 O 1.23655 0.00000 0.00000 0.00000 -0.00000 -0.07722 O 0.00000 0.00000 0.00000 0.00000 0.00000 0.06354 PRIMCOORD 2 2 1 O 1.23655 0.00000 0.00000 0.00000 -0.07071 -0.00000 O 0.00000 0.00000 0.00000 0.00000 0.07071 -0.00000 PRIMCOORD 3 2 1 O 1.23655 0.00000 0.00000 0.00000 -0.00000 0.06354 O 0.00000 0.00000 0.00000 0.00000 0.00000 0.07722 PRIMCOORD 4 2 1 O 1.23655 0.00000 0.00000 -0.07071 -0.00000 0.00000 O 0.00000 0.00000 0.00000 -0.07071 0.00000 0.00000 PRIMCOORD 5 2 1 O 1.23655 0.00000 0.00000 0.00000 -0.07071 -0.00000 O 0.00000 0.00000 0.00000 0.00000 -0.07071 -0.00000 PRIMCOORD 6 2 1 O 1.23655 0.00000 0.00000 -0.07071 0.00000 0.00000 O 0.00000 0.00000 0.00000 0.07071 0.00000 0.00000
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