From cbarreteau at cea.fr Thu Jun 3 09:26:01 2004
From: cbarreteau at cea.fr (Cyrille Barreteau)
Date: Thu, 03 Jun 2004 09:26:01 +0200
Subject: [Pw_forum] non collinear magnetism
Message-ID: <40BED289.8010509@cea.fr>
dear pwscf users,
I have a question concerning non-collinear magnetism and
example 13. In the two cases fe.pen.in and fe.angl.in
the system is made of a simple bcc iron with only one atom per
unit cell, therefore I do not really see the meaning of
non-collinear magnetism.
If there is no spin-orbit all direction are equivalent and therefore
the direction of magnetization is arbitrary. In that case I do not
understand the meaning of imposing a spin direction...
By the way is spin-orbit implemented in pwscf?
There is surely a point that I am missing. Maybe the code is doing
a spin wave calculation with a given wave length and uses the generalized
Bloch theorem...
thanks in advance
cyrille
--
============================================================
| Cyrille Barreteau | phone:+33 (0)1 69 08 29 51 |
| CEA Saclay | |
| DSM/DRECAM/SPCSI | fax : +33 (0)1 69 08 84 46 |
| Batiment 462 | |
| 91191 Gif sur Yvette Cedex | email: cbarreteau at cea.fr |
| FRANCE | |
| ~~~~~~~~~~~~~~~~~~~~~~~~ |
| web : http://www-drecam.cea.fr/spcsi/groupe1.htm |
============================================================
From sbraccia at sissa.it Thu Jun 3 10:04:29 2004
From: sbraccia at sissa.it (carlo sbraccia)
Date: Thu, 03 Jun 2004 10:04:29 +0200
Subject: [Pw_forum] about neb
Message-ID: <1086249869.2610.30.camel@dhpc-4-04.sissa.it>
Dear Rongqin,
the meaning of Error= *** is the following:
it represents the norm of the "neb"-force-vector acting on each image
divided by the number of degrees of freedom. With "neb"-force-vector I
mean both PES forces and spring forces (projected according to the neb
algorithm) which should be zero on the minimum energy path.
error = *** is simply the largest Error on the images. This error is
used to check the convergence of the neb optimization (as is done in
standard ionic relaxations): when error < neb_thr convergence is
achieved.
The total energies are given in eV, the errors in eV/Angstrom.
In the forthcoming version of PWscf (present CVS version) the output of
neb will be improved in order to be clearer than now (units will be
explicitly written).
carlo sbraccia
From g0203654 at nus.edu.sg Fri Jun 4 11:12:10 2004
From: g0203654 at nus.edu.sg (Wu Rongqin)
Date: Fri, 4 Jun 2004 17:12:10 +0800
Subject: [Pw_forum] about neb
Message-ID: <07FF47DA7F34EF4F8700F35EE424493E01026A10@MBXSRV26.stu.nus.edu.sg>
Dear all,
I used the nudged elastic band method to calculate the energy barrier and reasonable results can be obtained. however, it is overestimated, I have to do correlation for vibrational zero point energy. Is it possible? If yes, then how?
Thanks
Rongqin woo
-----Original Message-----
From: pw_forum-admin at pwscf.org [mailto:pw_forum-admin at pwscf.org] On Behalf Of carlo sbraccia
Sent: 2004?6?3? 16:04
To: pw_forum at pwscf.org
Subject: [Pw_forum] about neb
Dear Rongqin,
the meaning of Error= *** is the following:
it represents the norm of the "neb"-force-vector acting on each image
divided by the number of degrees of freedom. With "neb"-force-vector I
mean both PES forces and spring forces (projected according to the neb
algorithm) which should be zero on the minimum energy path.
error = *** is simply the largest Error on the images. This error is
used to check the convergence of the neb optimization (as is done in
standard ionic relaxations): when error < neb_thr convergence is
achieved.
The total energies are given in eV, the errors in eV/Angstrom.
In the forthcoming version of PWscf (present CVS version) the output of
neb will be improved in order to be clearer than now (units will be
explicitly written).
carlo sbraccia
_______________________________________________
Pw_forum mailing list
Pw_forum at pwscf.org
http://www.democritos.it/mailman/listinfo/pw_forum
From degironc at sissa.it Fri Jun 4 12:02:13 2004
From: degironc at sissa.it (Stefano de Gironcoli)
Date: Fri, 04 Jun 2004 12:02:13 +0200
Subject: [Pw_forum] about neb
References: <07FF47DA7F34EF4F8700F35EE424493E01026A10@MBXSRV26.stu.nus.edu.sg>
Message-ID: <40C048A5.5000209@sissa.it>
The straightforward, though expensive, way would to compute all phonon
frequencies for the initial state and for the saddle-point (discarding
the imaginary one) using the phonon code . This should give you also the
prefactor.
Beware however that in this way you are not including quantum tunneling,
though.
If you find a better way everybody would be interested.
stefano
Wu Rongqin wrote:
>Dear all,
>
>I used the nudged elastic band method to calculate the energy barrier and reasonable results can be obtained. however, it is overestimated, I have to do correlation for vibrational zero point energy. Is it possible? If yes, then how?
>Thanks
>Rongqin woo
>
>
From cbarreteau at cea.fr Fri Jun 4 12:17:09 2004
From: cbarreteau at cea.fr (Cyrille Barreteau)
Date: Fri, 04 Jun 2004 12:17:09 +0200
Subject: [Pw_forum] about neb
References: <07FF47DA7F34EF4F8700F35EE424493E01026A10@MBXSRV26.stu.nus.edu.sg> <40C048A5.5000209@sissa.it>
Message-ID: <40C04C25.8090101@cea.fr>
Just a small comment concerning the question of Rongqin woo.
What do you mean by overestimated? Does it mean you have
an experimental result and the value you find with pwscf is too
high? In anyway I would be surpised that taking into account
the vibrational zero point energy would make a huge difference.
However as pointed out by Stefano a phonon calculation can give
you access to the prefactor but of course you do not get
quantum tunneling, which can be important for very light atoms.
cyrille
Stefano de Gironcoli wrote:
> The straightforward, though expensive, way would to compute all phonon
> frequencies for the initial state and for the saddle-point (discarding
> the imaginary one) using the phonon code . This should give you also the
> prefactor.
> Beware however that in this way you are not including quantum tunneling,
> though.
>
> If you find a better way everybody would be interested.
>
> stefano
>
> Wu Rongqin wrote:
>
>
>>Dear all,
>>
>>I used the nudged elastic band method to calculate the energy barrier
and reasonable results can be obtained. however, it is overestimated,
I have to do correlation for vibrational zero point energy. Is it possible?
If yes, then how?
>>Thanks
>>Rongqin woo
>>
>>
>
>
>
> _______________________________________________
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum
--
============================================================
| Cyrille Barreteau | phone:+33 (0)1 69 08 29 51 |
| CEA Saclay | |
| DSM/DRECAM/SPCSI | fax : +33 (0)1 69 08 84 46 |
| Batiment 462 | |
| 91191 Gif sur Yvette Cedex | email: cbarreteau at cea.fr |
| FRANCE | |
| ~~~~~~~~~~~~~~~~~~~~~~~~ |
| web : http://www-drecam.cea.fr/spcsi/groupe1.htm |
============================================================
From FB153746 at ATIL.CEA.FR Fri Jun 4 13:12:54 2004
From: FB153746 at ATIL.CEA.FR (=?iso-8859-1?Q?BOUYER_Fr=E9d=E9ric_153746?=)
Date: Fri, 4 Jun 2004 13:12:54 +0200
Subject: [Pw_forum] Pseudos conversion
Message-ID: <601BA98F9E8C7645B7A0052ADBFCC714066EB820@atil.valrho.cea.fr>
Dear PWscf users,
I would like to know if anyone had make changes in the fhi2upf program (in
the upftools directory) in order to have the NLCC core corrections.
Many thanks in advance.
Regards,
F. Bouyer
****************************************
CEA VHR MARCOULE
F. Bouyer
DTCD / SECM / LCLT - B?t 208
BP 17171
30207 Bagnols-sur-C?ze Cedex - France
Tel : (+33)4 66 79 69 04
Fax : (+33)4 66 79 66 20
Email : frederic.bouyer at cea.fr
****************************************
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From katalin.gaal-nagy at physik.uni-regensburg.de Fri Jun 4 16:00:58 2004
From: katalin.gaal-nagy at physik.uni-regensburg.de (Katalin Gaal-Nagy)
Date: Fri, 4 Jun 2004 16:00:58 +0200 (MEST)
Subject: [Pw_forum] Pseudos conversion
Message-ID: <200406041401.i54E13nc008249@rrzd1.rz.uni-regensburg.de>
Dear F. Bouyer,
there are (to my knowledge) no automatics in order to put the NLCC into the
UPF-file. Usually you have the NLCC in some additional file, not in the
fhi-file. So you convert the "usual" fhi-file with fhi2upf and then you simply
put the values of the NLCC by hand to the file between the and the
expressions. Take care about the factor 4*pi*r^2, which can be
included into the NLCC and which has to be removed. The format of the NLCC is
written in the file UPF in the upftools-directory.
Have fun,
Katalin
>
> Dear PWscf users,
>
> I would like to know if anyone had make changes in the fhi2upf program (in
> the upftools directory) in order to have the NLCC core corrections.
> Many thanks in advance.
>
> Regards,
>
> F. Bouyer
From giannozz at nest.sns.it Sun Jun 6 17:25:07 2004
From: giannozz at nest.sns.it (Paolo Giannozzi)
Date: Sun, 6 Jun 2004 17:25:07 +0200
Subject: [Pw_forum] Pseudos conversion
In-Reply-To: <200406041401.i54E13nc008249@rrzd1.rz.uni-regensburg.de>
References: <200406041401.i54E13nc008249@rrzd1.rz.uni-regensburg.de>
Message-ID: <200406061725.07256.giannozz@nest.sns.it>
On Friday 04 June 2004 16:00, Katalin Gaal-Nagy wrote:
> Take care about the factor 4*pi*r^2, which can be included
> into the NLCC and which has to be removed.
that's exactly the problem....do you know for sure that
rho_nlcc(FHI) = \sum f_{nl} R_{nl}(r)^2
where R_{nl} is the radial part of the KS orbitals with
occupancies f_{nl}, i.e.
rho_nlcc(FHI) = 4pi r^2 rho_nlcc(UPF)
or is it just a guess?
Paolo
--
Paolo Giannozzi e-mail: giannozz at nest.sns.it
Scuola Normale Superiore Phone: +39/050-509876, Fax:-563513
Piazza dei Cavalieri 7 I-56126 Pisa, Italy
From giannozz at nest.sns.it Sun Jun 6 17:40:37 2004
From: giannozz at nest.sns.it (Paolo Giannozzi)
Date: Sun, 6 Jun 2004 17:40:37 +0200
Subject: [Pw_forum] non collinear magnetism
In-Reply-To: <40BED289.8010509@cea.fr>
References: <40BED289.8010509@cea.fr>
Message-ID: <200406061740.37023.giannozz@nest.sns.it>
On Thursday 03 June 2004 09:26, Cyrille Barreteau wrote:
> I have a question concerning non-collinear magnetism and
> example 13. In the two cases fe.pen.in and fe.angl.in
> the system is made of a simple bcc iron with only one atom per
> unit cell, therefore I do not really see the meaning of
> non-collinear magnetism.
> If there is no spin-orbit all direction are equivalent and therefore
> the direction of magnetization is arbitrary. In that case I do not
> understand the meaning of imposing a spin direction...
those examples are there for testing purposes only, I think
> By the way is spin-orbit implemented in pwscf?
it will be soon; it is already available in the CVS version, at you risk
Paolo
--
Paolo Giannozzi e-mail: giannozz at nest.sns.it
Scuola Normale Superiore Phone: +39/050-509876, Fax:-563513
Piazza dei Cavalieri 7 I-56126 Pisa, Italy
From g0203654 at nus.edu.sg Mon Jun 7 07:09:23 2004
From: g0203654 at nus.edu.sg (Wu Rongqin)
Date: Mon, 7 Jun 2004 13:09:23 +0800
Subject: [Pw_forum] about neb
Message-ID: <07FF47DA7F34EF4F8700F35EE424493E01022051@MBXSRV26.stu.nus.edu.sg>
Dear all,
I am doing calculations on small molecular adsorption on metal surface. One of the important issue on this is the vibrational modes. I saw example9 calculated the norm mode of SiH4, is it possible to calculate the norm modes of SiH4 absorbed on a surface? This is an interesting issue.
Rongqin Woo
-----Original Message-----
From: pw_forum-admin at pwscf.org [mailto:pw_forum-admin at pwscf.org] On Behalf Of Stefano de Gironcoli
Sent: 2004?6?4? 18:02
To: pw_forum at pwscf.org
Subject: Re: [Pw_forum] about neb
The straightforward, though expensive, way would to compute all phonon
frequencies for the initial state and for the saddle-point (discarding
the imaginary one) using the phonon code . This should give you also the
prefactor.
Beware however that in this way you are not including quantum tunneling,
though.
If you find a better way everybody would be interested.
stefano
Wu Rongqin wrote:
>Dear all,
>
>I used the nudged elastic band method to calculate the energy barrier and reasonable results can be obtained. however, it is overestimated, I have to do correlation for vibrational zero point energy. Is it possible? If yes, then how?
>Thanks
>Rongqin woo
>
>
_______________________________________________
Pw_forum mailing list
Pw_forum at pwscf.org
http://www.democritos.it/mailman/listinfo/pw_forum
From giannozz at nest.sns.it Mon Jun 7 12:31:45 2004
From: giannozz at nest.sns.it (Paolo Giannozzi)
Date: Mon, 7 Jun 2004 12:31:45 +0200
Subject: [Pw_forum] about neb
In-Reply-To: <07FF47DA7F34EF4F8700F35EE424493E01022051@MBXSRV26.stu.nus.edu.sg>
References: <07FF47DA7F34EF4F8700F35EE424493E01022051@MBXSRV26.stu.nus.edu.sg>
Message-ID: <200406071231.45606.giannozz@nest.sns.it>
On Monday 07 June 2004 07:09, Wu Rongqin wrote:
> is it possible to calculate the norm modes of SiH4 absorbed on a surface?
of course it is, but it may be difficult to get reliable estimates for typical
measured quantites, i.e. changes in frequencies and cross sections
upon adsorption
Paolo
--
Paolo Giannozzi e-mail: giannozz at nest.sns.it
Scuola Normale Superiore Phone: +39/050-509876, Fax:-563513
Piazza dei Cavalieri 7 I-56126 Pisa, Italy
From g0203654 at nus.edu.sg Mon Jun 7 14:54:12 2004
From: g0203654 at nus.edu.sg (Wu Rongqin)
Date: Mon, 7 Jun 2004 20:54:12 +0800
Subject: [Pw_forum] about neb
Message-ID: <07FF47DA7F34EF4F8700F35EE424493E01026A14@MBXSRV26.stu.nus.edu.sg>
Dear dr. Paolo,
Can you tell me how?
Thanks
Rongqin
-----Original Message-----
From: pw_forum-admin at pwscf.org [mailto:pw_forum-admin at pwscf.org] On Behalf Of Paolo Giannozzi
Sent: 2004?6?7? 18:32
To: pw_forum at pwscf.org
Subject: Re: [Pw_forum] about neb
On Monday 07 June 2004 07:09, Wu Rongqin wrote:
> is it possible to calculate the norm modes of SiH4 absorbed on a surface?
of course it is, but it may be difficult to get reliable estimates for typical
measured quantites, i.e. changes in frequencies and cross sections
upon adsorption
Paolo
--
Paolo Giannozzi e-mail: giannozz at nest.sns.it
Scuola Normale Superiore Phone: +39/050-509876, Fax:-563513
Piazza dei Cavalieri 7 I-56126 Pisa, Italy
_______________________________________________
Pw_forum mailing list
Pw_forum at pwscf.org
http://www.democritos.it/mailman/listinfo/pw_forum
From baroni at sissa.it Mon Jun 7 15:03:09 2004
From: baroni at sissa.it (Stefano Baroni)
Date: Mon, 7 Jun 2004 15:03:09 +0200
Subject: [Pw_forum] about neb
In-Reply-To: <07FF47DA7F34EF4F8700F35EE424493E01026A14@MBXSRV26.stu.nus.edu.sg>
References: <07FF47DA7F34EF4F8700F35EE424493E01026A14@MBXSRV26.stu.nus.edu.sg>
Message-ID: <062688BA-B883-11D8-A693-000A95CDDD16@sissa.it>
The same way as for any other system, I guess (i.e. a free SiH4
molecule)
For the standpoint of a computer, a "surface" is nothing but a big
molecule with periodic boundary conditions.
As any molecule is treated with periodic boundary conditions in PWscf,
you see that there won't be much difference
(if not for the different weight of the two calculations). Both systems
(a free and an adsorbed molecule) require some
thinking before unleashing supercomputers, though ...
Stefano Baroni
On Jun 7, 2004, at 2:54 PM, Wu Rongqin wrote:
> Dear dr. Paolo,
>
> Can you tell me how?
>
> Thanks
>
> Rongqin
>
> -----Original Message-----
> From: pw_forum-admin at pwscf.org [mailto:pw_forum-admin at pwscf.org] On
> Behalf Of Paolo Giannozzi
> Sent: 2004?6?7? 18:32
> To: pw_forum at pwscf.org
> Subject: Re: [Pw_forum] about neb
>
> On Monday 07 June 2004 07:09, Wu Rongqin wrote:
>
>> is it possible to calculate the norm modes of SiH4 absorbed on a
>> surface?
>
> of course it is, but it may be difficult to get reliable estimates for
> typical
> measured quantites, i.e. changes in frequencies and cross sections
> upon adsorption
>
> Paolo
> --
> Paolo Giannozzi e-mail: giannozz at nest.sns.it
> Scuola Normale Superiore Phone: +39/050-509876, Fax:-563513
> Piazza dei Cavalieri 7 I-56126 Pisa, Italy
> _______________________________________________
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum
> _______________________________________________
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum
>
---
Stefano Baroni --- SISSA & DEMOCRITOS National Simulation Center
via Beirut 2-4 34014 Trieste Grignano /
[+39] 040 3787 406 (tel) -528
(fax)
Please, if possible, don't send me MS Word or PowerPoint attachments
Why? See: http://www.gnu.org/philosophy/no-word-attachments.html
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From g0203654 at nus.edu.sg Mon Jun 7 15:33:40 2004
From: g0203654 at nus.edu.sg (Wu Rongqin)
Date: Mon, 7 Jun 2004 21:33:40 +0800
Subject: [Pw_forum] about neb
Message-ID: <07FF47DA7F34EF4F8700F35EE424493E01022052@MBXSRV26.stu.nus.edu.sg>
Dear Dr. Baroni,
Can you give me some detailed suggestion?
I have some idea but need your opinion:
Firstly , do a calculation on the free SiH4 molecule,
Secondly, do a phonon calculation on a clean surface.
Third, do a phonon calculation on the SiH4+surface,.
Due to the masses difference, the mode frequencies of the surface and SiH4, the mode frequencies of SiH4 may be selected out.
Do you think it is a way?
Regards
Rongqin woo
-----Original Message-----
From: pw_forum-admin at pwscf.org [mailto:pw_forum-admin at pwscf.org] On Behalf Of Stefano Baroni
Sent: 2004?6?7? 21:03
To: pw_forum at pwscf.org
Subject: Re: [Pw_forum] about neb
The same way as for any other system, I guess (i.e. a free SiH4 molecule)
For the standpoint of a computer, a "surface" is nothing but a big molecule with periodic boundary conditions.
As any molecule is treated with periodic boundary conditions in PWscf, you see that there won't be much difference
(if not for the different weight of the two calculations). Both systems (a free and an adsorbed molecule) require some
thinking before unleashing supercomputers, though ...
Stefano Baroni
On Jun 7, 2004, at 2:54 PM, Wu Rongqin wrote:
Dear dr. Paolo,
Can you tell me how?
Thanks
Rongqin
-----Original Message-----
From: pw_forum-admin at pwscf.org [mailto:pw_forum-admin at pwscf.org] On Behalf Of Paolo Giannozzi
Sent: 2004?6?7? 18:32
To: pw_forum at pwscf.org
Subject: Re: [Pw_forum] about neb
On Monday 07 June 2004 07:09, Wu Rongqin wrote:
is it possible to calculate the norm modes of SiH4 absorbed on a surface?
of course it is, but it may be difficult to get reliable estimates for typical
measured quantites, i.e. changes in frequencies and cross sections
upon adsorption
Paolo
--
Paolo Giannozzi e-mail: giannozz at nest.sns.it
Scuola Normale Superiore Phone: +39/050-509876, Fax:-563513
Piazza dei Cavalieri 7 I-56126 Pisa, Italy
_______________________________________________
Pw_forum mailing list
Pw_forum at pwscf.org
http://www.democritos.it/mailman/listinfo/pw_forum
_______________________________________________
Pw_forum mailing list
Pw_forum at pwscf.org
http://www.democritos.it/mailman/listinfo/pw_forum
---
Stefano Baroni --- SISSA & DEMOCRITOS National Simulation Center
via Beirut 2-4 34014 Trieste Grignano / ?[+39] 040 3787 406 (tel) -528 (fax)
Please, if possible, don't send me MS Word or PowerPoint attachments
Why? See: http://www.gnu.org/philosophy/no-word-attachments.html
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From baroni at sissa.it Mon Jun 7 15:40:59 2004
From: baroni at sissa.it (Stefano Baroni)
Date: Mon, 7 Jun 2004 15:40:59 +0200
Subject: [Pw_forum] about neb
In-Reply-To: <07FF47DA7F34EF4F8700F35EE424493E01022052@MBXSRV26.stu.nus.edu.sg>
References: <07FF47DA7F34EF4F8700F35EE424493E01022052@MBXSRV26.stu.nus.edu.sg>
Message-ID: <4F353756-B888-11D8-A693-000A95CDDD16@sissa.it>
The second step, though instructive, may not be strictly necessary
Also look at the displacement patterns (phonon eigenvectors)
Stefano
On Jun 7, 2004, at 3:33 PM, Wu Rongqin wrote:
> Dear Dr. Baroni,
>
> ?
>
> Can you give me some detailed suggestion?
>
> I have some idea but need your opinion:
>
> Firstly , do a calculation on the free SiH4 molecule,
>
> Secondly, do a phonon calculation on a clean surface.
>
> Third, do a phonon calculation on the SiH4+surface,.
>
> Due to the masses difference, the mode frequencies of the surface and
> SiH4, the mode frequencies of SiH4 may be selected out.
>
> Do you think it is a way?
>
> ?
>
> Regards
>
> ?
>
> Rongqin woo
>
> ?
>
> -----Original Message-----
> From: pw_forum-admin at pwscf.org [mailto:pw_forum-admin at pwscf.org] On
> Behalf Of Stefano Baroni
> Sent: 2004?6?7? 21:03
> To: pw_forum at pwscf.org
> Subject: Re: [Pw_forum] about neb
>
> ?
>
> The same way as for any other system, I guess (i.e. a free SiH4
> molecule)
>
> ?
>
> For the standpoint of a computer, a "surface" is nothing but a big
> molecule with periodic boundary conditions.
>
> As any molecule is treated with periodic boundary conditions in
> PWscf, you see that there won't be much difference
>
> (if not for the different weight of the two calculations). Both
> systems (a free and an adsorbed molecule) require some
>
> thinking before unleashing supercomputers, though ...
>
> ?
>
> Stefano Baroni
>
> ?
>
> On Jun 7, 2004, at 2:54 PM, Wu Rongqin wrote:
>
> ?
>
> Dear dr. Paolo,
>
> ?
>
> Can you tell me how?
>
> ?
>
> Thanks
>
> ?
>
> Rongqin
>
> ?
>
> -----Original Message-----
>
> From: pw_forum-admin at pwscf.org [mailto:pw_forum-admin at pwscf.org] On
> Behalf Of Paolo Giannozzi
>
> Sent: 2004?6?7? 18:32
>
> To: pw_forum at pwscf.org
>
> Subject: Re: [Pw_forum] about neb
>
> ?
>
> On Monday 07 June 2004 07:09, Wu Rongqin wrote:
>
> ?
>
> is it possible to calculate the norm modes of SiH4 absorbed on a
> surface?
>
> ?
>
> of course it is, but it may be difficult to get reliable estimates for
> typical
>
> measured quantites, i.e. changes in frequencies and cross sections
>
> upon adsorption
>
> ?
>
> Paolo
>
> --
>
> Paolo Giannozzi e-mail: giannozz at nest.sns.it
>
> Scuola Normale Superiore Phone: +39/050-509876, Fax:-563513
>
> Piazza dei Cavalieri 7 I-56126 Pisa, Italy
>
> _______________________________________________
>
> Pw_forum mailing list
>
> Pw_forum at pwscf.org
>
> http://www.democritos.it/mailman/listinfo/pw_forum
>
> _______________________________________________
>
> Pw_forum mailing list
>
> Pw_forum at pwscf.org
>
> http://www.democritos.it/mailman/listinfo/pw_forum
>
> ?
>
> ---
>
> Stefano Baroni --- SISSA & DEMOCRITOS National Simulation Center
>
> via Beirut 2-4 34014 Trieste Grignano / ?[+39] 040 3787 406 (tel)
> -528 (fax)
>
> ?
>
> Please, if possible, don't send me MS Word or PowerPoint attachments
>
> Why? See: http://www.gnu.org/philosophy/no-word-attachments.html
>
---
Stefano Baroni --- SISSA & DEMOCRITOS National Simulation Center
via Beirut 2-4 34014 Trieste Grignano /
[+39] 040 3787 406 (tel) -528
(fax)
Please, if possible, don't send me MS Word or PowerPoint attachments
Why? See: http://www.gnu.org/philosophy/no-word-attachments.html
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From g0203654 at nus.edu.sg Wed Jun 9 11:27:59 2004
From: g0203654 at nus.edu.sg (Wu Rongqin)
Date: Wed, 9 Jun 2004 17:27:59 +0800
Subject: [Pw_forum] about neb
Message-ID: <07FF47DA7F34EF4F8700F35EE424493E01026A18@MBXSRV26.stu.nus.edu.sg>
Dear Dr. Baroni,
I have thought of another way to calculate the norm mode of small
molecular absorbed on a surface.
The idea is quite simple. Since the frequency is related closely to the
mass, then in the input file, I can set the mass of atoms in the slab to
a very large value so that the correspondent frequencies are greatly
lowered so the norm mode of small molecular absorbed can be figured out.
Just give me some comments on this and how to give a zero point energy
correlation
Regards
Rongqin
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From baroni at sissa.it Wed Jun 9 12:01:14 2004
From: baroni at sissa.it (Stefano Baroni)
Date: Wed, 9 Jun 2004 12:01:14 +0200
Subject: [Pw_forum] about neb
In-Reply-To: <07FF47DA7F34EF4F8700F35EE424493E01026A18@MBXSRV26.stu.nus.edu.sg>
References: <07FF47DA7F34EF4F8700F35EE424493E01026A18@MBXSRV26.stu.nus.edu.sg>
Message-ID:
In this way you will not obtain the normal modes of the physical system
you are interested in, but those of a fictitious system with different
masses. frequencies will be different, displacement patterns will be
different.
The fact that you cannot disentangle exactly the modes in which the
adsorbed molecule vibrates from those in which the substrate atoms
vibrate is not an artifact of the calculation, but a fact of nature you
have to leave with (at least if you are interested in the way Nature
behaves rather than just in the output of a computer simulation).
best wishes,
SB
On Jun 9, 2004, at 11:27 AM, Wu Rongqin wrote:
> ?
>
> ?Dear Dr. Baroni,
>
> ?
>
> I have thought of another way to calculate the norm mode of small
> molecular absorbed on a surface.
>
> The idea is quite simple. Since the frequency is related closely to
> the mass, then in the input file, I can set the mass of atoms in the
> slab to a very large value so that the correspondent frequencies are
> greatly lowered so the norm mode of small molecular absorbed can be
> figured out.
>
> Just give me some comments on this and how to give a zero point energy
> correlation
>
> ?
>
> Regards
>
> ?
>
> Rongqin
>
> ?
>
---
Stefano Baroni --- SISSA & DEMOCRITOS National Simulation Center
via Beirut 2-4 34014 Trieste Grignano /
[+39] 040 3787 406 (tel) -528
(fax)
Please, if possible, don't send me MS Word or PowerPoint attachments
Why? See: http://www.gnu.org/philosophy/no-word-attachments.html
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From cbarreteau at cea.fr Wed Jun 9 14:31:47 2004
From: cbarreteau at cea.fr (Cyrille Barreteau)
Date: Wed, 09 Jun 2004 14:31:47 +0200
Subject: [Pw_forum] about neb
References: <07FF47DA7F34EF4F8700F35EE424493E01026A18@MBXSRV26.stu.nus.edu.sg>
Message-ID: <40C70333.3020609@cea.fr>
dear Rongqin
Obviously doing a calculation with fictious substrate masses will lead
to a totally different system which has nothing to do with your
original system. However one could imagine calculating local spectral
density of states that would allow you to extract the contribution
of your molecule from the total spectrum. If the coupling with your
substrate is small this contribution will be rather well separated
from the substrate spectrum...
good luck
cyrille
Stefano Baroni wrote:
> In this way you will not obtain the normal modes of the physical system
> you are interested in, but those of a fictitious system with different
> masses. frequencies will be different, displacement patterns will be
> different.
> The fact that you cannot disentangle exactly the modes in which the
> adsorbed molecule vibrates from those in which the substrate atoms
> vibrate is not an artifact of the calculation, but a fact of nature you
> have to leave with (at least if you are interested in the way Nature
> behaves rather than just in the output of a computer simulation).
>
> best wishes,
> SB
>
> On Jun 9, 2004, at 11:27 AM, Wu Rongqin wrote:
>
>
>
> Dear Dr. Baroni,
>
>
>
> I have thought of another way to calculate the norm mode of small
> molecular absorbed on a surface.
>
> The idea is quite simple. Since the frequency is related closely to
> the mass, then in the input file, I can set the mass of atoms in the
> slab to a very large value so that the correspondent frequencies are
> greatly lowered so the norm mode of small molecular absorbed can be
> figured out.
>
> Just give me some comments on this and how to give a zero point
> energy correlation
>
>
>
> Regards
>
>
>
> Rongqin
>
>
>
> ---
> Stefano Baroni --- SISSA & DEMOCRITOS National Simulation Center
> via Beirut 2-4 34014 Trieste Grignano / [+39] 040 3787 406 (tel) -528
> (fax)
>
> Please, if possible, don't send me MS Word or PowerPoint attachments
> Why? See: http://www.gnu.org/philosophy/no-word-attachments.html
>
--
From katalin.gaal-nagy at physik.uni-regensburg.de Thu Jun 10 15:28:32 2004
From: katalin.gaal-nagy at physik.uni-regensburg.de (Katalin Gaal-Nagy)
Date: Thu, 10 Jun 2004 15:28:32 +0200 (MEST)
Subject: [Pw_forum] Pseudos conversion
Message-ID: <200406101328.i5ADSX5S001318@rrzd2.rz.uni-regensburg.de>
Dear Paolo,
> > Take care about the factor 4*pi*r^2, which can be included
> > into the NLCC and which has to be removed.
> that's exactly the problem....do you know for sure that
> rho_nlcc(FHI) = \sum f_{nl} R_{nl}(r)^2
> where R_{nl} is the radial part of the KS orbitals with
> occupancies f_{nl}, i.e.
> rho_nlcc(FHI) = 4pi r^2 rho_nlcc(UPF)
> or is it just a guess?
In my case it was clear, because the person who generated the PS told me that
the NLCC is in the form 4*pi*r^2*charge, but I don't know if this is in general
like this, because I guess there exist also other programs which can calculate
som NLCC for a given potential. As soon as I know more about the NLCC from the
fhi-code I will tell you.
Greetings,
Katalin
From jlgr at super.unam.mx Fri Jun 11 00:37:00 2004
From: jlgr at super.unam.mx (Jose Luis Gordillo Ruiz)
Date: Thu, 10 Jun 2004 17:37:00 -0500 (CDT)
Subject: [Pw_forum] compiling serial cp with cxml ..
Message-ID:
Hi all,
I'm trying to compile the serial version of CP in an alpha server,
with Tru64 and CXML (using fft from this library).
However, at link step I got this error:
Unresolved:
cfft3_
cfft3s_
cfft3b_
these functions aren't part of CXML fft library
somebody can figure out where can i find these functions?
thanks in advance
PS my make.sys is like this:
# Use fft routines from the dxml or cxml library:
CPPFLAGS = -D__ALPHA -DDXML -I$(OSHOME)/include
# Use precompiled fftw library (version <= 2.1.5, NOT v.3!)
#
# In this case, specify also how to load the fftw library (FFTW_LIB)
# and the path to the fftw.h include file (FFTW_INC_DIR). Example:
# FFTW_LIB= -L/usr/local/src/fftw-2.1.3/fftw/.libs -lfftw
# FFTW_INC_DIR=/usr/local/src/fftw-2.1.3/fftw
# CPPFLAGS = -D__ALPHA -D__FFTW -I$(OSHOME)/include \
# -I$(FFTW_INC_DIR)
# Use the local copy of fftw
#
#CPPFLAGS = -D__ALPHA -D__FFTW -D__USE_INTERNAL_FFTW \
# -I$(OSHOME)/include -I./
#
# Fortran compiler:
#
F90 = f90
F77 = f90
CC = cc
# options suggested by Ph. Baranek:
# FFLAGS =-O5 -fast -big_endian -fpe0 -check underflow -real_size 64 \
# -align dcommons -align records
# -big_endian allows to read files generated on other (big endian)
machines
FFLAGS = -O -real_size 64 -align dcommons -align records
# Flags for FPMD
# FFLAGS = -double_size 64 -fpconstant -real_size 64 -fast \
# -math_library fast -tune ev68
#
F77FLAGS = $(FFLAGS)
F90FLAGS = $(FFLAGS) -free -cpp $(CPPFLAGS)
CCFLAGS = -O $(CPPFLAGS)
#
# This is needed to tell the compiler where modules are
#
MODULEFLAG= -I$(OSHOME)/Modules -I$(OSHOME)/PW -I$(OSHOME)/PH
#
# Libraries:
# If you have dxml or cxml libraries, use
LIBS = -ldxml $(FFTW_LIB)
# BEWARE: if you have a dxml version with buggy blas/lapack, use
# LIBS = -llapack -lblas -ldxml $(FFTW_LIB)
#
# Loader:
#
LD=$(F90)
LDFLAGS = $(OSHOME)/flib/ptools.a $(OSHOME)/flib/flib.a
$(OSHOME)/clib/clib.a $(LIBS)
#
# ar:
#
AR = ar
ARFLAGS = rv
From shamim7862002 at yahoo.com Thu Jun 10 23:14:18 2004
From: shamim7862002 at yahoo.com (shamim akhtar)
Date: Thu, 10 Jun 2004 14:14:18 -0700 (PDT)
Subject: [Pw_forum] Problem Using MPI
Message-ID: <20040610211418.28185.qmail@web40801.mail.yahoo.com>
Hello,
When I run a MPI program then the following error has shown. I dont know why..Some times it shows and sometimes not...sometimes work properly....
What the problem?
What i have done is here..
From eyvaz_isaev at yahoo.com Fri Jun 11 17:00:30 2004
From: eyvaz_isaev at yahoo.com (Eyvaz Isaev)
Date: Fri, 11 Jun 2004 08:00:30 -0700 (PDT)
Subject: [Pw_forum] Problem Using MPI
In-Reply-To: <20040610211418.28185.qmail@web40801.mail.yahoo.com>
Message-ID: <20040611150030.94918.qmail@web60308.mail.yahoo.com>
Hi,
I am not MPI expert, but according to your report I
can guess that you have hardware problem. Perhaps your
network works not properly.
But it is just my guess.
Bests,
Eyvaz.
--- shamim akhtar wrote:
> Hello,
> When I run a MPI program then the following error
> has shown. I dont know why..Some times it shows and
> sometimes not...sometimes work properly....
> What the problem?
> What i have done is here..
> From master node i send 55 data set to 5 processors
> by a MPI_SEND() with in a loop...
> the slaves receive by MPI_Recv() with in a loop and
> again send all data set to the master by using
> MPI_Recv() with in a loop..
> The loop is used for how many data they receive and
> how many data they send just keep the track...
>
>
> $ time mpirun -np 5 a.out
> 0 - MPI_RECV : Message truncated
> [0] Aborting program !
> [0] Aborting program!
> I am processor 4I am processor 3I am processor 2I am
> processor 1/home/software/mpich-1.2.5/bin/mpirun:
> line 1: 1699 Broken pipe
> /home/st027364/sort/a.out -p4pg
> /home/st027364/sort/PI1551 -p4wd /home/st027364/sort
> real 0m7.002s
> user 0m0.100s
> sys 0m0.110s
>
>
> Thanks..
> Shamim
>
>
> ---------------------------------
> Do you Yahoo!?
> Friends. Fun. Try the all-new Yahoo! Messenger
__________________________________
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From giannozz at nest.sns.it Mon Jun 14 15:34:52 2004
From: giannozz at nest.sns.it (Paolo Giannozzi)
Date: Mon, 14 Jun 2004 15:34:52 +0200
Subject: [Pw_forum] compiling serial cp with cxml ..
In-Reply-To: <200406141349.03500.p.giannozzi@sns.it>
References: <200406141349.03500.p.giannozzi@sns.it>
Message-ID: <200406141534.52791.giannozz@nest.sns.it>
On Friday 11 June 2004 00:37, Jose Luis Gordillo Ruiz wrote:
> I'm trying to compile the serial version of CP in an alpha server,
> with Tru64 and CXML (using fft from this library).
>
> However, at link step I got this error:
>
> Unresolved:
> cfft3_
> cfft3s_
> cfft3b_
>
> [...] somebody can figure out where can i find these functions?
you cannot find them because they don't exist, save for a few
exotic machines. You have either to implement them or to use
FFTW. The simplest thing to do is to uncomment the field after
the line:
# Use the local copy of fftw
Paolo
--
Paolo Giannozzi e-mail: giannozz at nest.sns.it
Scuola Normale Superiore Phone: +39/050-509876, Fax:-563513
Piazza dei Cavalieri 7 I-56126 Pisa, Italy
From subhra at uiuc.edu Tue Jun 22 22:51:38 2004
From: subhra at uiuc.edu (Subhradip Ghosh)
Date: Tue, 22 Jun 2004 16:51:38 -0400
Subject: [Pw_forum] Contour.x
Message-ID: <30243ba2.549ce163.823ae00@expms6.cites.uiuc.edu>
Hi,
I was trying to do charge density plots using PWSCF. In the
INPUT_CHDENS file there is an option '1' in 'output_format'
which labels it as the 'format suitable for contour.x'.
However, I didn't find any executable contour.x in the
package. Am I missing something or there indeed is no
contour.x? I guess that it is a programme for drawing charge
density contours without using plotrho.x. Therefore I am
interested in having a go at it if possible.
Thanks in advance,
Subhradip
*******************************************************************
Subhradip Ghosh
Post doctoral Fellow
Department of Materials Science & Engineering
University of Illinois at Urbana-Champaign
********************************************************************
Office Home
**********************************************************************
MSEB 312C * 2001 South Orchard Street Apt D
1304 W Green street * Urbana, IL-61801
Urbana, IL-61801 * Phone # 2173841824
Phone # 2173336584 * E-mail: subhradip at yahoo.com
E-mail: subhra at uiuc.edu *
************************************************************************
From a.antons at fz-juelich.de Wed Jun 23 09:02:47 2004
From: a.antons at fz-juelich.de (A.Antons)
Date: Wed, 23 Jun 2004 09:02:47 +0200
Subject: [Pw_forum] Contour.x
References: <30243ba2.549ce163.823ae00@expms6.cites.uiuc.edu>
Message-ID: <40D92B17.9B48D1E5@fz-juelich.de>
Hi Subhra,
sorry that I can't help you at the moment. My mother is moving to her new
appartment, and I promised to help her, so am going to take a few days off.
If you can postpone it until next week, I will have some time then.
Armin
Subhradip Ghosh wrote:
> Hi,
>
> I was trying to do charge density plots using PWSCF. In the
> INPUT_CHDENS file there is an option '1' in 'output_format'
> which labels it as the 'format suitable for contour.x'.
> However, I didn't find any executable contour.x in the
> package. Am I missing something or there indeed is no
> contour.x? I guess that it is a programme for drawing charge
> density contours without using plotrho.x. Therefore I am
> interested in having a go at it if possible.
>
> Thanks in advance,
>
> Subhradip
> *******************************************************************
> Subhradip Ghosh
> Post doctoral Fellow
> Department of Materials Science & Engineering
> University of Illinois at Urbana-Champaign
> ********************************************************************
> Office Home
> **********************************************************************
> MSEB 312C * 2001 South Orchard Street Apt D
> 1304 W Green street * Urbana, IL-61801
> Urbana, IL-61801 * Phone # 2173841824
> Phone # 2173336584 * E-mail: subhradip at yahoo.com
> E-mail: subhra at uiuc.edu *
> ************************************************************************
> _______________________________________________
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum
--
Dr. Armin Antons Forschungszentrum Juelich GmbH
Tel: +49-2461-61-4246 Institut fuer Festkoerperforschung
Fax: +49-2461-61-2620 Postfach 1913
E-Mail: a.antons at fz-juelich.de D-52425 Juelich
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From degironc at sissa.it Wed Jun 23 09:14:21 2004
From: degironc at sissa.it (Stefano de Gironcoli)
Date: Wed, 23 Jun 2004 09:14:21 +0200
Subject: [Pw_forum] Contour.x
References: <30243ba2.549ce163.823ae00@expms6.cites.uiuc.edu>
Message-ID: <40D92DCD.8020309@sissa.it>
I don't know if/where contour.x can be downloaded at present, but
setting output_format=2 allows you to use plotrho.x (not fancy but
distributed with PWSCF)
setting output_format=3 allows you to use XCrysDen (very sophisticated,
GPL-distributed software, available at http://www.xcrysden.org/)
setting output_format=0 allows you to use gnuplot (distributed with any
linux kernel)
best regards,
Stefano de Gironcoli
Subhradip Ghosh wrote:
>Hi,
>
>I was trying to do charge density plots using PWSCF. In the
>INPUT_CHDENS file there is an option '1' in 'output_format'
>which labels it as the 'format suitable for contour.x'.
>However, I didn't find any executable contour.x in the
>package. Am I missing something or there indeed is no
>contour.x? I guess that it is a programme for drawing charge
>density contours without using plotrho.x. Therefore I am
>interested in having a go at it if possible.
>
>Thanks in advance,
>
>Subhradip
>*******************************************************************
> Subhradip Ghosh
> Post doctoral Fellow
> Department of Materials Science & Engineering
> University of Illinois at Urbana-Champaign
>********************************************************************
>Office Home
>**********************************************************************
>MSEB 312C * 2001 South Orchard Street Apt D
>1304 W Green street * Urbana, IL-61801
>Urbana, IL-61801 * Phone # 2173841824
>Phone # 2173336584 * E-mail: subhradip at yahoo.com
>E-mail: subhra at uiuc.edu *
>************************************************************************
>_______________________________________________
>Pw_forum mailing list
>Pw_forum at pwscf.org
>http://www.democritos.it/mailman/listinfo/pw_forum
>
>
From duanxm at ts.infn.it Wed Jun 23 16:48:21 2004
From: duanxm at ts.infn.it (Xiangmei Duan)
Date: Wed, 23 Jun 2004 16:48:21 +0200 (MET DST)
Subject: [Pw_forum] A question
Message-ID:
Dear all,
I met a problem when I run the job to do the relax or nscf
calculation using the newest version (2.0.3).
(No problem for the very old version 1.0.3)
Here is the error information:
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
from c_bands : error # 1
too many bands are not converged
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
stopping ...
Any advice ?
Thanks in advance,
best regards,
XM
From a.soon at auckland.ac.nz Thu Jun 24 00:52:12 2004
From: a.soon at auckland.ac.nz (Aloysius Soon Sze Lok)
Date: Thu, 24 Jun 2004 10:52:12 +1200
Subject: [Pw_forum] Use of "tefield" and "edir"
Message-ID: <200406241052.12282.a.soon@auckland.ac.nz>
Dear all,
I'm interested in using the PWscf package to perform some periodic slab
calculations, investigating surface geometry and energetics. I understand
that one will have to use the keywords "tefield", "edir" and possibly some
others to do dipole correction for single-sided adsorption studies.
I'm asking for help in this area: What is the general use of these keywords
and what are some of the implications to the calculations.
Many thanks in advance.
--
Aloysius Soon SL
Postgraduate Student
Structural & Computational Chemistry
Chemistry Department
The University Of Auckland, New Zealand
Phone: +64 9 373 7599 ext 88291
Email: a.soon at auckland.ac.nz
From giannozz at nest.sns.it Thu Jun 24 09:57:52 2004
From: giannozz at nest.sns.it (Paolo Giannozzi)
Date: Thu, 24 Jun 2004 09:57:52 +0200
Subject: [Pw_forum] A question
In-Reply-To:
References:
Message-ID: <200406240957.52672.giannozz@nest.sns.it>
On Wednesday 23 June 2004 16:48, Xiangmei Duan wrote:
> I met a problem when I run the job to do the relax or nscf
> calculation using the newest version (2.0.3).
> (No problem for the very old version 1.0.3)
> Here is the error information:
> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
> from c_bands : error # 1
> too many bands are not converged
> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
> Any advice ?
if it used to work, it should still work. Check carefully your input data
Paolo
--
Paolo Giannozzi e-mail: giannozz at nest.sns.it
Scuola Normale Superiore Phone: +39/050-509876, Fax:-563513
Piazza dei Cavalieri 7 I-56126 Pisa, Italy
From FB153746 at ATIL.CEA.FR Thu Jun 24 11:04:07 2004
From: FB153746 at ATIL.CEA.FR (=?iso-8859-1?Q?BOUYER_Fr=E9d=E9ric_153746?=)
Date: Thu, 24 Jun 2004 11:04:07 +0200
Subject: [Pw_forum] Phonons calculations
Message-ID: <601BA98F9E8C7645B7A0052ADBFCC714066EB861@atil.valrho.cea.fr>
Dear users,
Could you please tell me where to find the input data format of the phgc.x
program ?
If it is in the cg_readin.f90 file, could you please explain a little the
following keywords ?
- asr
- tr2_ph
- nmodes
- deltatau
- nderiv (I guess the finite differences +a and -a applied to each
position of all atoms, and not only +a)
- first
- last
Many thanks in advance.
Fr?d?ric
****************************************
CEA VHR MARCOULE
F. Bouyer
DTCD / SECM / LCLT - B?t 208
BP 17171
30207 Bagnols-sur-C?ze Cedex - France
Tel : (+33) 4 66 79 69 04
Fax : (+33) 4 66 79 66 20
Email : frederic.bouyer at cea.fr
****************************************
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From ylyj2000 at yahoo.com Thu Jun 24 19:12:48 2004
From: ylyj2000 at yahoo.com (Li Yu)
Date: Thu, 24 Jun 2004 10:12:48 -0700 (PDT)
Subject: [Pw_forum] question about maxirr in input file for phonon
Message-ID: <20040624171248.69753.qmail@web50401.mail.yahoo.com>
Hi, everyone,
I am calculating some big unit cell. I only need
the frequencies of acoustic modes. So I sepcify
maxirr=5. However, the output file only tell me that
the program
finishes the first 5 modes calcualation, but doesn't
write the frequencies of them. Does anyone has this
experience? Can you give some help? Thanks a lot.
Li Yang
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From giannozz at nest.sns.it Mon Jun 28 12:25:19 2004
From: giannozz at nest.sns.it (Paolo Giannozzi)
Date: Mon, 28 Jun 2004 12:25:19 +0200
Subject: [Pw_forum] Phonons calculations
In-Reply-To: <601BA98F9E8C7645B7A0052ADBFCC714066EB861@atil.valrho.cea.fr>
References: <601BA98F9E8C7645B7A0052ADBFCC714066EB861@atil.valrho.cea.fr>
Message-ID: <200406281225.19455.giannozz@nest.sns.it>
On Thursday 24 June 2004 11:04, BOUYER Fr?d?ric 153746 wrote:
> Could you please tell me where to find the input data format of the
> phgc.x program ?
here:
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First, an explanation and a warning: the code phcg.x contained in
the Gamma/ subdirectory is a specialized phonon code, calculating
phonon modes only at Gamma (q=0), and using only Gamma (k=0) for
the sum over the Brillouin Zone. It performs direct minimization
of the energy functional expanded at second order in the atomic
displacements. The code was written having molecular applications
in mind : Raman and IR spectra calculations in C60 (see JCP 100,
p.8537, 1994) and later in models of the GFP chromophore (Chem.Phys.
287/1-2, p.33, 2003). The (non resonant) Raman cross sections are
calculated by finite differences of the dielectric tensor with
respect to small atomic displacements. This method is simple but
slow and is made obsolete by the use of the (2n+1) theorem. Unless
you know what you are doing, you shouldn't use this code for the
calculation of Raman coefficients.
Note that:
- the code reads a file produced by pw.x with Gamma point only and
Gamma-point special tricks (half of the plane waves and so on)
- the symmetry is used in a different way wrt all other PWscf codes:
only inequivalent atoms are displaced. This has an historical reason:
C60 has just 3 inequivalent atoms when put into in a cubic cell with
standard orientation (the isolated molecule has 1 inequivalent atom)
- the code saves partial and final results in files "restart_e" and
"restartph". Remove those files if you want to start from scratch,
otherwise the code will restart from previous data.
Input:
title (a string of characters)
&inputph [variable1=value1, variable2=value2,...] /
displacement patterns (optional, see below)
Input variables as in the phonon code:
outdir
prefix
fildyn
epsil
trans
tr2_ph Note that Conjugate-Gradient algorithm stops when
|| A\delta\psi - B || < tr2_ph, where A and B define
the DFT functional expanded at second order:
E^{(2)} = (1/2) (\delta\psi A \delta\psi) - B\delta\psi
Variables specific to this code:
asr use Acoustic Sum Rule to reduce by 3 the number of phonon
calculations to be performed (used only if trans=.true.)
nmodes use the specified displacement patterns, provided after the
namelist as nmodes vectors, each with 3*nat components
(nat=number of atoms); nmodes < 3*nat is allowed (I think).
If not set, uses all 3*nat displacement patterns (one atom
at the time, along x, or y, or z)
Raman-specific variables for this code:
raman perform a calculation of Raman cross sections by finite
differences
deltatau finite difference (a.u.): typically a small but not too
small amount, something like 0.01 a.u, or so
nderiv type of finite derivative formula: nderiv=2 is a simple
two-point formula (two calculations per displacement)
[ f (-deltatau) + f(+deltatau) - 2 f(0) ] / 2/ deltatau^2
nderiv=4 is a four-point forumala (4 calculations / disp. )
first, last
calculate raman intensities only for phonon modes from the
"first" to the "last", using those phonon modes as displ.
patterns (requires nderiv*(last-first+1) calculations).
If not set, calculate cross sections for all atomic displ.
then the raman intensities for all phonon modes.
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--
Paolo Giannozzi e-mail: giannozz at nest.sns.it
Scuola Normale Superiore Phone: +39/050-509876, Fax:-563513
Piazza dei Cavalieri 7 I-56126 Pisa, Italy