[Pw_forum] negtive values for TA when using q2r.x

[Paolo Giannozzi]

On Sunday 01 January 2006 03:17, li yan wrote:

>    i use q2r.x  to calculate the phonon dispersion curves for AgF.
>    at 3GPa, there are many negative values for TA in the brillouin zone.
>    then i just calculated one of these points, but i got a positive values.
>    then i used  6*6*6 q mesh, no improvement is found.

the Fourier interpolation performed by q2r.x yields the original phonon
frequencies at the q-points of the grid in q-space. If it doesn't, there is
something wrong somewhere in the procedure

P.
-- 
Paolo Giannozzi             e-mail:  giannozz at nest.sns.it
Scuola Normale Superiore    Phone:   +39/050-509876, Fax:-563513 
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