The ABINIT Users Mailing List ( CLOSED )

["Zhenhua Zeng" <myid520@163.com>]

Your problem is that the q-point you used, i.e. 0.5 0.5 0.5, is not belong to 
the 
k-point grid used in the same calculation. Namely, you used a general 
q-point, not a
special q-point with respect to k-poing grid.
For example, If you used 8x8x8 k-pointn grid in calcualtion, then the all 
q-point points
reduced from 8x8x8 or 4x4x4 or 2x2x2 q-point grid are special points which 
connect k-points,
however the q-points reduced from 7x7x7 or 6x6x6 or 5x5x5 or 3x3x3 are just 
general q-points.

The phonon calculations for two type q-poinst use different strategy, while 
you used strategy 
for special q-point to general one.

Please see the tutorial
http://www.abinit.org/documentation/helpfiles/for-v5.8/tutorial/lesson_rf1.html#6

 and help file for detial. 
http://www.abinit.org/documentation/helpfiles/for-v5.8/users/respfn_help.html#4

Best Wishes                      
Zhenhua Zeng

-------------------------------------------------------------
From：H.Y Liu
sent:：2009-12-03 12:45:44
To：forum@abinit.org
Subject：[abinit-forum] I have questions about calculating phonon

>
>hello
>
>I want to calculate phonon frequency with single point. for example,
>0.5 0.5 0.5.
>but I have no idea if I should give cartesian or crystal direction in
>input file.
>when I give cartesian direction, it give me error information.
>
>-Pnwffil: ERROR
>-P-0000   The file ./tmp/o_DS1_WFK cannot be used to start the
>-P-0000   present calculation. It was asked that the wavefunctions be
>accurate, but
>-P-0000   at least one of the k points could not be generated from a
>symmetrical one.
>-P-0000   dksqmax=    1.035807E-06
>-P-0000   Action: check your wf file and k point input variables
>-P-0000     (e.g. kptopt or shiftk might be wrong in the present
>dataset or the preparatory one.
>-P-0000
>-P-0000  leave_new : decision taken to exit ...
>-P-0000  leave_new : synchronization done...
>-P-0000  leave_new : exiting...
>
>I don't know why, I want to know how to solve it.
>
>can abinit calculate any q wavevector ?
>
>thanks!
>-- 
>-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=**=-=**=-=**=-=*=-=*=-=*=-=*=-=*=-
> Hanyu Liu(刘寒雨),
> MS.
> State key  Laboratory of Superhard Materials, Jilin University, China
> Email: liuhanyu08@mails.jlu.edu.cn    ouuing@gmail.com
>.
S
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