# [Pw_forum] QHA frequency is higher than *.freq

KangYun Song songsong19840614 at hotmail.com
Sun Nov 13 12:18:45 CET 2011

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Yun Song,Kang
Department Physical Science and Technology of  Inner Mongolia University.

From: songsong19840614 at hotmail.com
To: pw_forum at pwscf.org
Date: Fri, 11 Nov 2011 12:55:14 +0000
Subject: Re: [Pw_forum] QHA frequency is higher than *.freq

Hi,
The pdos is not similar to phonon dispersion and the frequency is not negative from ph.x.

Yun Song,Kang
Department Physical Science and Technology of  Inner Mongolia University.

From: songsong19840614 at hotmail.com
To: pw_forum at pwscf.org
Date: Thu, 10 Nov 2011 12:15:50 +0000
Subject: [Pw_forum] QHA frequency is higher than *.freq

Hi,
Recently,I calculated the phonon dispersion.And I use the *.fc from matdyn q2r.x to calculate frequecy and pdos.But this is a problem the freqency from matdyn.x of QHA is higher than *.freq from matdyn.x of phonon dispersion calculation.Why?Could anyone help me?The other material I use this method did not meet this problem.
The matdyn.in of QHA is:

&input
amass(1)=*,
amass(2)=*,
asr='crystal',
flfrc=*.fc,
flfrq='frequency'
&end
1183
-0.33333   0.57735   0.81850   1.00000
-0.30555   0.52924   0.75029   1.00000
-0.30555   0.57735   0.75029   1.00000
………………

The matdyn.in of phonon dispersion calculating is :

&input
asr='simple',  amass(1)=*, amass(2)=*,
flfrc='*.fc', flfrq='*.freq' ,la2F=.false. ,
/
85
0.0000000   0.0000000   0.3092146, wk =   0.0235294
0.0555560   0.0000000   0.3092146, wk =   0.0235294
0.1111110  -0.0000006   0.3092146, wk =   0.0235294
0.1666670   0.0000006   0.3092146, wk =   0.0235294
0.2222220   0.0000000   0.3092146, wk =   0.0235294
0.2777780   0.0000000   0.3092146, wk =   0.0235294
…………

Yun Song,Kang
Department Physical Science and Technology of  Inner Mongolia University.

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