[Pw_forum] Balance the efficiency and veracity of PWscf vs. other DFT codes.

[Axel Kohlmeyer]

On Sat, 5 Jul 2008, zhaohscas wrote:

HZ> Hi all,

hi!
 
HZ> When the system under study is large, i.e., including hundreds of 
HZ> atoms or more, in this case, form the point of balancing the 
HZ> efficiency and veracity, whether the PWscf is suitable for such 
HZ> computation or not?  Furthermore, in this case, which will be more 
HZ> promising DFT code(s)?

this is a strange kind of question to ask to a mailing list that
supports a specific code. what do you expect people to answer? 
QE is complete crap and does not run correctly on anything and
does not scale to boot?? you are better off using code X??? 
i hope not.

of course, QE does run as accurate as possible within the confines
of using DFT with plane waves and pseudopotentials, modulo the 
occasional bug that every large, versatile and thus complex software 
package contains. of course we would like you to use it and not 
something else. of course, that are weaknesses, but the code offers
a lot of possiblilities for good performance and scaling and people
are continuously trying to improve it. it cannot beat the scaling
of the underlying physics, though, and one always has to make a tradeoff
between the flexibility, capabilities, and maintainability of a code 
and its absolute performance.

since there is no "one-size fits all" kind of solution, the best
choice of approach (and thus code) always depends on the specific
problem at hand.

HZ> Any help or hints would be appreciated.

my suggestion: try it and see for yourself.

cheers,
   axel.

HZ> Sincerely yours, 				
HZ> --------------
HZ> Hongsheng Zhao <zhaohscas at yahoo.com.cn> 
HZ> Xinjiang Technical Institute of Physics and Chemistry
HZ> Chinese Academy of Sciences 
HZ> GnuPG DSA: 0xD10849
HZ> 2008-07-05
HZ> 
HZ> _______________________________________________
HZ> Pw_forum mailing list
HZ> Pw_forum at pwscf.org
HZ> http://www.democritos.it/mailman/listinfo/pw_forum
HZ> 

-- 
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Axel Kohlmeyer   akohlmey at cmm.chem.upenn.edu   http://www.cmm.upenn.edu
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