Dear developer and users:
Exactly follow the userguide, I am trying to calculate the phonon.
Firstly I make a self-consistent calculation with
K_POINTS automatic
8 8 8 0 0 0
After the calculation convergent, I start the ph.x calculation. But the
calculation is extremely slow, thus I goto
the output-file, and find a strange thing.
For some q-qoint, I find;
number of k points= 1024 Marzari-Vanderbilt smearing, width (Ry)= 0.0500
I understand that phonon may break some symmetry, but how it can go to
1024-k-point when I use 8-8-8 mesh?
I already use "start_q=X, last_q=X, recover=.true.," to separate q-point. I
also use parallel to speed up the calculation.
But it is still extremely slow. My system has only 12 atoms per unit cell, and
it seems that some q-point
(where it requires 1024 k-points) may need one month!
I don't know if there is other method to speed up the calculation?
Thanks!
Xiangang Wan
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
http://www.democritos.it/pipermail/pw_forum/attachments/20110821/60662fe2/attachment.htm
