[Pw_forum] Doubt in Phonon calculations

[Bipul Rakshit]

Dear Hui Wang,
THanks for you kind advice. Just tell me I have to do the symmetry
analysis manually, or there is some simple method to do so?
thanks

On 8/11/09, xirainbow <nkxirainbow at gmail.com> wrote:
> Dear Bipul Rakshit:
>
>>My doubt is if you see the O/P of phonon (phonon.out) file, it seems it is
> going to calculate all >the 60 modes.
>>But as far as I know at gamma atleast few modes are degenerate and acoustic
> is zero.
> I look at your  uploaded files and found the following content:
> " ibrav=  0, celldm(1) =14.62476638, nat=  20, ntyp= 4,
> CELL_PARAMETERS cubic
>   0.73727   0.00000   0.00000
>   0.00000   1.00000   0.00000
>   0.00000   0.00000   0.71933"
> The symmetry of your system is very low.
> I think you can do certain symmetry analysis for your system, determine how
> many degenerated mode are before calculation.
>
> ____________________________________
> Hui Wang
> School of physics, Nankai University, Tianjin, China
>


-- 
Dr. Bipul Rakshit
Research Associate,
S N Bose Centre for Basic Sciences,
Salt Lake,
Kolkata 700 098
India