[Pw_forum] Phonon axsf does not move in XCrysden

[Tone Kokalj]

On Mon, 2017-03-27 at 04:40 +0000, Huang, Xu wrote:
> 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.)

The vibrational modes in xcrysden are visualized with arrows only,
without any "motion" (this is not a bug as stated by Lorenzo, but it is
the way it is meant). This way you can use the vibrational-mode-with-
arrow's picture, say, in the paper. 

You can tune the display of arrows via "Modify->Force Settings" menu
(these arrows are called "forces" in xcrysden because in the XSF file
the displacement patterns are specified in the same way as forces, i.e.
each atom has additional three components after the coordinates specs).

For your particular example of O2 molecule, you can easily recognize
three translational, two rotational and one bond-stretching modes from
"arrows".

Best regards, Tone
-- 
J. Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia 
(tel: +386-1-477-3523 // fax: +386-1-251-9385)