[Pw_forum] phonon dispersion

[shudong wang]

Dear developers:

I performed phonon dispersion of two-dimensional Si with two layer silicon
atoms passivated by H atom (Si4H2) ,and there are two branches have frequncy
higher than others(in red), and the result is :
&plot nbnd=  18, nks=  61 /
           0.000000  0.000000  0.000000
 -16.5775   -7.8790   -3.1558   97.8351  105.6592  222.2850
 390.0047  474.5206  478.3406  482.2919  494.0081  502.5633
 602.3562  620.0962  648.4555  660.1258 2110.7548 2116.3744
           0.016667  0.016667  0.000000
 -16.1481    4.8616   17.1698   98.9575  107.0761  222.1388
 389.3945  474.3367  478.1513  482.3187  493.1097  502.8504
 602.4038  620.8876  648.1560  660.0547 2110.3105 2116.3290
           0.033333  0.033333  0.000000
 -14.9035   13.0400   36.1211  102.1200  111.2414  221.7379
 387.5912  473.7711  477.6237  482.2742  490.9342  503.3493
 602.4055  623.2746  647.2722  659.9022 2109.0949 2116.0984
........
........
........
........

my input files are:

&inputph
tr2_ph=1.0d-10,
prefix='s2',
fildvscf='s2dv',
amass(1)=28.0855,
amass(2)=1.0
outdir='/home/sdwang/aa/tmp/',
fildyn='s2.dyn',
elph=.false.,
trans=.true.,
ldisp=.true.
nq1=4, nq2=4, nq3=1
/
 &input
asr='simple',amass(1)=28.0855,amass(2)=1.0,
flfrc='s2444.fc',flfrq='s2444.freq',la2f=.false.,dos=.false.,
/
61
 0.000000  0.000000  0.000000  1.00
 0.016667  0.016667  0.000000  1.00
 0.033333  0.033333  0.000000  1.00
 0.050000  0.050000  0.000000  1.00
.......

&input
zasr='simple', fildyn='s2.dyn', flfrc='s2444.fc', la2F=.false.
/

What's the matter?

Thanks!

S.D.Wang

Southeast University in Nanjing ,China.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20100415/9a9d866a/attachment.html>