[Pw_forum] vibrational frequencies

[Axel Kohlmeyer]

for all practical purposes, there are no differences between phonons
and infrared frequencies. axel.

On 1/18/09, Jonas Baltrusaitis <jasius_1 at yahoo.com> wrote:
> I see the problem now. I am so used to calculating Hessian upon each atom
> displacement in non-plane wave type calculations. Are there any examples on
> how to setup calculations to eventually get IR frequencies?
>
> JOnas
>
>
> --- On Sun, 1/18/09, j.antonio.montoya at gmail.com
> <j.antonio.montoya at gmail.com> wrote:
>
>> From: j.antonio.montoya at gmail.com <j.antonio.montoya at gmail.com>
>> Subject: Re: [Pw_forum] vibrational frequencies
>> To: jasius_1 at yahoo.com, "PWSCF Forum" <pw_forum at pwscf.org>
>> Date: Sunday, January 18, 2009, 3:23 PM
>> Dear Jonas,
>>
>> From the phonon calculation you can automatically get the
>> IR and Raman active frequencies, and with a bit more of
>> effort also the intensities.
>>
>> If you don't know the relation between phonons and the
>> frequencies you are looking for, please read a book on solid
>> state physics, or in IR spectroscopy.
>>
>> Javier Montoya
>> CIW, DC 20015
>> USA
>> Sent via BlackBerry by AT&T
>>
>> -----Original Message-----
>> From: Jonas Baltrusaitis <jasius_1 at yahoo.com>
>>
>> Date: Sun, 18 Jan 2009 14:27:29
>> To: PWSCF Forum<pw_forum at pwscf.org>; lan
>> haiping<lanhaiping at gmail.com>
>> Subject: Re: [Pw_forum] vibrational frequencies
>>
>>
>> Well, I did my homework but couldn't find anything
>> about calculating vibrational frequencies (infrared
>> spectrum). Only phonon frequencies... IAny clues?
>>
>> JOnas Baltrusaitis
>> University of IOwa
>>
>>
>> --- On Sat, 1/17/09, lan haiping
>> <lanhaiping at gmail.com> wrote:
>>
>> > From: lan haiping <lanhaiping at gmail.com>
>> > Subject: Re: [Pw_forum] vibrational frequencies
>> > To: jasius_1 at yahoo.com, "PWSCF Forum"
>> <pw_forum at pwscf.org>
>> > Date: Saturday, January 17, 2009, 9:40 PM
>> > Hi,
>> > Please take a look at www.quantum-espresso.org or the
>> > userguide along with
>> > the QE package.
>> > A simple answer is "Yes"!
>> >
>> > And please supply your affiliation!
>> >
>> > best
>> >
>> > On Sun, Jan 18, 2009 at 1:36 PM, Jonas Baltrusaitis
>> > <jasius_1 at yahoo.com>wrote:
>> >
>> > > Can pwscf calculate vibrational frequencies
>> (IR)?
>> > >
>> > >
>> > >
>> > > _______________________________________________
>> > > Pw_forum mailing list
>> > > Pw_forum at pwscf.org
>> > >
>> http://www.democritos.it/mailman/listinfo/pw_forum
>> > >
>> >
>> >
>> >
>> > --
>> > Hai-Ping Lan
>> > Department of Electronics ,
>> > Peking University , Bejing, 100871
>> > lanhaiping at gmail.com, hplan at pku.edu.cn
>>
>>
>>
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>
>
>
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-- 
=======================================================================
Axel Kohlmeyer   akohlmey at cmm.chem.upenn.edu   http://www.cmm.upenn.edu
  Center for Molecular Modeling   --   University of Pennsylvania
Department of Chemistry, 231 S.34th Street, Philadelphia, PA 19104-6323
tel: 1-215-898-1582,  fax: 1-215-573-6233,  office-tel: 1-215-898-5425
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If you make something idiot-proof, the universe creates a better idiot.