[Pw_forum] Pw_forum Digest, Vol 42, Issue 43
Riping WANG
wang.riping.81 at gmail.com
Mon Dec 27 01:07:25 CET 2010
Der prof. Paolo,
Thanks very much to your reply.
1. Re: ion_radius (Paolo Giannozzi)
WANG Riping
2010.12.27
On 25 December 2010 12:36, <pw_forum-request at pwscf.org> wrote:
> Send Pw_forum mailing list submissions to
> pw_forum at pwscf.org
>
> To subscribe or unsubscribe via the World Wide Web, visit
> http://www.democritos.it/mailman/listinfo/pw_forum
> or, via email, send a message with subject or body 'help' to
> pw_forum-request at pwscf.org
>
> You can reach the person managing the list at
> pw_forum-owner at pwscf.org
>
> When replying, please edit your Subject line so it is more specific
> than "Re: Contents of Pw_forum digest..."
>
>
> Today's Topics:
>
> 1. Re: ion_radius (Paolo Giannozzi)
> 2. how does the calculation scales with number of processors
> (mohnish pandey)
> 3. Re: how does the calculation scales with number of processors
> (Stefano de Gironcoli)
> 4. Re: how does the calculation scales with number of processors
> (mohnish pandey)
> 5. Re: how does the calculation scales with number of processors
> (Paolo Giannozzi)
> 6. Merry Christmas (jiayudai)
> 7. About the difference between the energy obtained from
> geometry optimization and single energy calculation. (Hongsheng Zhao)
> 8. About the relationship between enthalpy and pressure.
> (Hongsheng Zhao)
> 9. Re: About the relationship between enthalpy and pressure.
> (Stefano de Gironcoli)
> 10. Re: About the difference between the energy obtained from
> geometry optimization and single energy calculation. (Prasenjit Ghosh)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Fri, 24 Dec 2010 09:56:00 +0100
> From: Paolo Giannozzi <giannozz at democritos.it>
> Subject: Re: [Pw_forum] ion_radius
> To: PWSCF Forum <pw_forum at pwscf.org>
> Message-ID: <5B32AABF-A8DA-4C29-8850-9250578A7450 at democritos.it>
> Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed
>
>
> On Dec 24, 2010, at 7:56 , Riping WANG wrote:
>
> > In example18, for cp.x practice. I found the " ion_radius(1)
> > and ion_radius(2) " in the input file.
> > Could you please tell me something about this input parameter, and
> > how to set?
>
> usuallly you do not need to set it: the default value should be fine.
> ion_radius is the width of a gaussian distribution of charge replacing
> the point charge of the (pseudo-)nucleus. It should be big enough
> to ensure convergence of the total energy in G-space, small enough
> to yield negligible overlap between gaussians. Valus around 0.8 are
> usually fine. The total energy and forces should not change if
> ion_radius changes.
>
> P.
> ---
> Paolo Giannozzi, Dept of Chemistry&Physics, Univ. Udine
> via delle Scienze 208, 33100 Udine, Italy
> Phone +39-0432-558216, fax +39-0432-558222
>
>
>
>
>
>
> ------------------------------
>
> Message: 2
> Date: Fri, 24 Dec 2010 15:12:19 +0530
> From: mohnish pandey <mohnish.iitk at gmail.com>
> Subject: [Pw_forum] how does the calculation scales with number of
> processors
> To: PWSCF Forum <pw_forum at pwscf.org>
> Message-ID:
> <AANLkTimzcxdX+zRc4pHNYUQUU8Ph+qG7aiwggG=XyEnh at mail.gmail.com>
> Content-Type: text/plain; charset="iso-8859-1"
>
> Dear QE users,
> I am trying to see how the runtime scales with
> number of processors. I did the same calculation using one node with eight
> processors on one cluster and 8 nodes with total 56 processors on other
> cluster but the time does not seem to scale linearly with the number of
> processors. Can anybody give me an idea how does the time scale with number
> of processors.
> Thanks a lot in advance.
>
> --
> Regards,
> MOHNISH,
> -----------------------------------------------------------------
> Mohnish Pandey
> Y6927262,5th Year dual degree student,
> Department of Chemical Engineering,
> IIT KANPUR, UP, INDIA
> -----------------------------------------------------------------
> -------------- next part --------------
> An HTML attachment was scrubbed...
> URL:
> http://www.democritos.it/pipermail/pw_forum/attachments/20101224/094c0e6d/attachment-0001.htm
>
> ------------------------------
>
> Message: 3
> Date: Fri, 24 Dec 2010 11:20:34 +0100
> From: Stefano de Gironcoli <degironc at sissa.it>
> Subject: Re: [Pw_forum] how does the calculation scales with number of
> processors
> To: PWSCF Forum <pw_forum at pwscf.org>
> Message-ID: <4D1473F2.9090302 at sissa.it>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> It strongly depends on the particular calculation and on the
> parallelization strategy you choose. Linear scaling would be the ideal
> scaling which you never get.
> The things to keep in mind are load balancing and communication
> overhead. This last is affected by your communication network latency
> and bandwidth ... As a general rule the bigger the calculation the
> easier is to scale.
> It may be useful to have a look at the final timing summary of a
> calculation to see the fraction of time spent in communication (FFT
> scatter/gather and reduce operations) compared with the total wall clock
> time for your system and how this changes for different settings.
> Another factor to keep in mind is RAM memory as with certain
> parallelization strategies you can trade some speed with increased memory.
>
> stefano
>
> mohnish pandey wrote:
> > Dear QE users,
> > I am trying to see how the runtime scales with
> > number of processors. I did the same calculation using one node with
> eight
> > processors on one cluster and 8 nodes with total 56 processors on other
> > cluster but the time does not seem to scale linearly with the number of
> > processors. Can anybody give me an idea how does the time scale with
> number
> > of processors.
> > Thanks a lot in advance.
> >
> >
> > ------------------------------------------------------------------------
> >
> > _______________________________________________
> > Pw_forum mailing list
> > Pw_forum at pwscf.org
> > http://www.democritos.it/mailman/listinfo/pw_forum
> >
>
>
>
> ------------------------------
>
> Message: 4
> Date: Fri, 24 Dec 2010 15:56:41 +0530
> From: mohnish pandey <mohnish.iitk at gmail.com>
> Subject: Re: [Pw_forum] how does the calculation scales with number of
> processors
> To: PWSCF Forum <pw_forum at pwscf.org>
> Message-ID:
> <AANLkTimwTeZ2R2tGkX4ztQL6KMi3PuYop7N+J1PDJZ3L at mail.gmail.com<AANLkTimwTeZ2R2tGkX4ztQL6KMi3PuYop7N%2BJ1PDJZ3L at mail.gmail.com>
> >
> Content-Type: text/plain; charset="iso-8859-1"
>
> Thanks a lot Dr. Stefano for your reply.
>
> On Fri, Dec 24, 2010 at 3:50 PM, Stefano de Gironcoli <degironc at sissa.it
> >wrote:
>
> > It strongly depends on the particular calculation and on the
> > parallelization strategy you choose. Linear scaling would be the ideal
> > scaling which you never get.
> > The things to keep in mind are load balancing and communication
> > overhead. This last is affected by your communication network latency
> > and bandwidth ... As a general rule the bigger the calculation the
> > easier is to scale.
> > It may be useful to have a look at the final timing summary of a
> > calculation to see the fraction of time spent in communication (FFT
> > scatter/gather and reduce operations) compared with the total wall clock
> > time for your system and how this changes for different settings.
> > Another factor to keep in mind is RAM memory as with certain
> > parallelization strategies you can trade some speed with increased
> memory.
> >
> > stefano
> >
> > mohnish pandey wrote:
> > > Dear QE users,
> > > I am trying to see how the runtime scales with
> > > number of processors. I did the same calculation using one node with
> > eight
> > > processors on one cluster and 8 nodes with total 56 processors on other
> > > cluster but the time does not seem to scale linearly with the number of
> > > processors. Can anybody give me an idea how does the time scale with
> > number
> > > of processors.
> > > Thanks a lot in advance.
> > >
> > >
> > >
> ------------------------------------------------------------------------
> > >
> > > _______________________________________________
> > > 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
> >
>
>
>
> --
> Regards,
> MOHNISH,
> -----------------------------------------------------------------
> Mohnish Pandey
> Y6927262,5th Year dual degree student,
> Department of Chemical Engineering,
> IIT KANPUR, UP, INDIA
> -----------------------------------------------------------------
> -------------- next part --------------
> An HTML attachment was scrubbed...
> URL:
> http://www.democritos.it/pipermail/pw_forum/attachments/20101224/e6654593/attachment-0001.htm
>
> ------------------------------
>
> Message: 5
> Date: Fri, 24 Dec 2010 11:28:22 +0100
> From: Paolo Giannozzi <giannozz at democritos.it>
> Subject: Re: [Pw_forum] how does the calculation scales with number of
> processors
> To: PWSCF Forum <pw_forum at pwscf.org>
> Message-ID: <E4B16AE1-0031-425C-988E-416268CBF5E0 at democritos.it>
> Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed
>
>
> On Dec 24, 2010, at 10:42 , mohnish pandey wrote:
>
> > Can anybody give me an idea how does the time scale with number of
> > processors.
>
> please see the user guide in particular chapter 3:
> http://www.quantum-espresso.org/user_guide/node15.html
> and this, in particular the "(Too) Frequently Asked Question"
> http://www.fisica.uniud.it/~giannozz/QE-Tutorial/<http://www.fisica.uniud.it/%7Egiannozz/QE-Tutorial/>
>
> P.
> ---
> Paolo Giannozzi, Dept of Chemistry&Physics, Univ. Udine
> via delle Scienze 208, 33100 Udine, Italy
> Phone +39-0432-558216, fax +39-0432-558222
>
>
>
>
>
>
> ------------------------------
>
> Message: 6
> Date: Fri, 24 Dec 2010 20:07:29 +0800
> From: "jiayudai" <daijiayu at nudt.edu.cn>
> Subject: [Pw_forum] Merry Christmas
> To: pw_forum at pwscf.org
> Message-ID: <EMWVIYDTKKFKAFNJEUDEIMZTWAFZ.daijiayu at nudt.edu.cn>
> Content-Type: text/plain; charset="gb2312"
>
> Mearry Christmas to every body.
>
> Good luck for us!
>
>
>
> ------------------------------
>
> Message: 7
> Date: Fri, 24 Dec 2010 22:30:44 +0800
> From: Hongsheng Zhao <zhaohscas at yahoo.com.cn>
> Subject: [Pw_forum] About the difference between the energy obtained
> from geometry optimization and single energy calculation.
> To: PWSCF Forum <pw_forum at pwscf.org>
> Message-ID: <232357947.20101224223044 at yahoo.com.cn>
> Content-Type: text/plain; charset=us-ascii
>
> Dear PWSCF users,
>
> The geometry optimization can give the minimal energy of our system. What's
> the difference between the energy obtained from geometry optimization and
> the single energy calculation?
>
> Best regards.
> --
> Hongsheng Zhao <zhaohscas at yahoo.com.cn>
> School of Physics and Electrical Information Science,
> Ningxia University, Yinchuan 750021, China
> GnuPG DSA: 0xD108493
> 2010-12-24
>
> __________________________________________________
> 赶快注册雅虎超大容量免费邮箱?
> http://cn.mail.yahoo.com
>
>
> ------------------------------
>
> Message: 8
> Date: Sat, 25 Dec 2010 09:50:43 +0800
> From: Hongsheng Zhao <zhaohscas at yahoo.com.cn>
> Subject: [Pw_forum] About the relationship between enthalpy and
> pressure.
> To: PWSCF Forum <pw_forum at pwscf.org>
> Message-ID: <1504855182.20101225095043 at yahoo.com.cn>
> Content-Type: text/plain; charset=us-ascii
>
> Dear PWSCF users,
>
> We all know that, the pressure-Volume, and energy--Volume curve can be
> obtained by fitting of EOS. But what's the relationship between enthalpy
> and pressure?
>
> Best regards.
> --
> Hongsheng Zhao <zhaohscas at yahoo.com.cn>
> School of Physics and Electrical Information Science,
> Ningxia University, Yinchuan 750021, China
> GnuPG DSA: 0xD108493
> 2010-12-25
>
> __________________________________________________
> 赶快注册雅虎超大容量免费邮箱?
> http://cn.mail.yahoo.com
>
>
> ------------------------------
>
> Message: 9
> Date: Sat, 25 Dec 2010 03:10:52 +0100
> From: Stefano de Gironcoli <degironc at sissa.it>
> Subject: Re: [Pw_forum] About the relationship between enthalpy and
> pressure.
> To: PWSCF Forum <pw_forum at pwscf.org>
> Message-ID: <4D1552AC.1090207 at sissa.it>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> Pressure is the thermodynamical variable upon which enthalpy depends
>
> If you know E(V) you can define H(P) = min_V ( E(V) + P V )
>
> Have a look in a book of thermodynamics.
>
> stefano
>
>
>
> Hongsheng Zhao wrote:
> > Dear PWSCF users,
> >
> > We all know that, the pressure-Volume, and energy--Volume curve can be
> obtained by fitting of EOS. But what's the relationship between enthalpy
> and pressure?
> >
> > Best regards.
> >
> > ------------------------------------------------------------------------
> >
> > _______________________________________________
> > Pw_forum mailing list
> > Pw_forum at pwscf.org
> > http://www.democritos.it/mailman/listinfo/pw_forum
> >
>
>
>
> ------------------------------
>
> Message: 10
> Date: Sat, 25 Dec 2010 09:06:09 +0530
> From: Prasenjit Ghosh <prasenjit.jnc at gmail.com>
> Subject: Re: [Pw_forum] About the difference between the energy
> obtained from geometry optimization and single energy calculation.
> To: PWSCF Forum <pw_forum at pwscf.org>
> Message-ID:
> <AANLkTin8_XS7tCn9KPWyYHhHCqS=Zo-oYjZpK-mjLnYW at mail.gmail.com>
> Content-Type: text/plain; charset=GB2312
>
> In geometry optimization you relax both the ionic coordinates and the
> electronic coordinates to obtain the minimum energy configuration. In
> a single energy calculation, you minimize only the electronic
> coordinates for a given fixed ionic position.
>
> Prasenjit
>
> On 24 December 2010 20:00, Hongsheng Zhao <zhaohscas at yahoo.com.cn> wrote:
> > Dear PWSCF users,
> >
> > The geometry optimization can give the minimal energy of our system.
> What's the difference between the energy obtained from geometry optimization
> and the single energy calculation?
> >
> > Best regards.
> > --
> > Hongsheng Zhao <zhaohscas at yahoo.com.cn>
> > School of Physics and Electrical Information Science,
> > Ningxia University, Yinchuan 750021, China
> > GnuPG DSA: 0xD108493
> > 2010-12-24
> >
> > __________________________________________________
> > ???????????????
> > http://cn.mail.yahoo.com
> >
> > _______________________________________________
> > Pw_forum mailing list
> > Pw_forum at pwscf.org
> > http://www.democritos.it/mailman/listinfo/pw_forum
> >
> >
>
>
>
> --
> PRASENJIT GHOSH,
> Assistant Professor,
> IISER Pune,
> First floor, Central Tower, Sai Trinity Building
> Garware Circle, Sutarwadi, Pashan
> Pune, Maharashtra 411021, India
>
> Phone: +91 (20) 2590 8203
> Fax: +91 (20) 2589 9790
>
>
> ------------------------------
>
> _______________________________________________
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum
>
>
> End of Pw_forum Digest, Vol 42, Issue 43
> ****************************************
>
--
******************************************************************************
WANG Riping
Ph.D student,
Institute for Study of the Earth's Interior,Okayama University,
827 Yamada, Misasa, Tottori-ken 682-0193, Japan
Tel: +81-858-43-3739(Office), 1215(Inst)
E-mail: wang.riping.81 at gmail.com
******************************************************************************
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20101227/3ef5bf67/attachment.html>
More information about the users
mailing list