[CPMD-list] CPMD Exercises

[Axel Kohlmeyer]

On Thu, 13 May 2004 kohsj at ihpc.a-star.edu.sg wrote:

AK> Dear Prof Kohlmeyer,
AK> 
AK> Thanks for your kind response.  I've proceeded on to the first
AK> exercise and managed to generate the output file.  I've used the
AK> potentials "H_GIA_BLYP", "H_SG_BLYP" and "H_SG_LDA" (hope you know
AK> what these files mean).
AK> 
AK> I noticed that there's this warning message:
AK> 
AK>  !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
AK>  WARNING! XC FUNCTIONALS INCONSISTENT FOR H_GIA_BLYP
AK>  !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
AK> 
AK> when the two potentials with subcript "BLYP" were used.  What do they
AK> mean?  Are there any implications for this?

yes. pseudopotentials should be created from an all-electron 
calculation with the same functional. so in your case, you
probably have to change the FUNCTIONAL keyword in the
&DFT section to FUNCTIONAL BLYP.


axel kohlmeyer.

p.s.: for the record. i am not a professor. ;-)

AK> 
AK> Thanks for your attention.
AK> 
AK> 
AK> Adrian.
AK> 
AK> 
AK> 
AK> 
AK> ----- Original Message -----
AK> From: Axel Kohlmeyer <axel.kohlmeyer at theochem.ruhr-uni-bochum.de>
AK> Date: Wednesday, May 12, 2004 3:48 pm
AK> Subject: Re: [CPMD-list] CPMD Exercises
AK> 
AK>  On Wed, 12 May 2004 kohsj at ihpc.a-star.edu.sg wrote:
AK>  
AK>  AK> Dear Prof Hutter,
AK>  
AK>  dear adrian,
AK>  
AK>  although i am not prof. hutter <g>, i hope i can provide 
AK>  the answers you need.
AK>  
AK>  AK> I'm currently trying out the exercises listed on your website.  
AK>  I'm on
AK>  AK> practice for the h2 molecule.  My questions are as follows:
AK>  AK> 
AK>  AK> 1.     What does it mean by the keyword "NEWCODE" under section 
AK>  &DFT?
AK>  there a two implementations of the functionals in CPMD. this activates
AK>  the newer one (which is also the default and recommended). this is
AK>  featured in the manual, but at the _end_ of the list of keywords.
AK>  
AK>  
AK>  AK> 2.  What do the contents under section &ATOMS refer to?  They 
AK>  couldn'tAK> be found anywhere in the manuals.
AK>  
AK>  the format of the &ATOMS section _is_ explained in the manual. just
AK>  look under 'Further details of the input'.
AK>  
AK>  AK> 3.  Also, I realized that there was a section in the Appendix
AK>  AK> explaining the generation of pseudopotentials for this set of
AK>  AK> practice.  Where and how will these be used?
AK>  
AK>  you can take the pseudopotentials you need from the pseudopotential
AK>  library in the CPMD dowload section. if you want to create 
AK>  pseudopotentials for CPMD yourself (not recommended if you are a 
AK>  beginner) or learn some more about their properties and derivation, 
AK>  then you can for example have a look at the documention provided
AK>  with paolo gianozzi's pseudopotential code. 
AK>  <" target="l">http://www.nest.sns.it/~giannozz/software.html>
AK>  
AK>  
AK>  AK> 4.  A general question... What are the most basic sections and
AK>  AK> keywords we need to use in creating an input file?  How are the
AK>  AK> pseudopotentials referred to in the input file?
AK>  
AK>  you need the sections &CPMD, &DFT, &SYSTEM, and &ATOMS.
AK>  the syntax of pseudopotential specification is discussed 
AK>  in the manual.
AK>  
AK>  as for the h2-example. some weeks ago, i started working on a
AK>  real cpmd-tutorial starting with the material from juerg hutters
AK>  homepage. since i can only work on it in my (currently very 
AK>  sparse) free time, there is very little there yet (basically only 
AK>  the h2 wavefunction optimization and the and a discussion of the 
AK>  input and output). also it has not been reviewed by anybody, 
AK>  so there are likely to be many errors or omissions.
AK>  
AK>  if this doesn't scare you, you can still have a peek at it at:
AK>  http://www.theochem.ruhr-uni-bochum.de/~axel.kohlmeyer/cpmd-
AK>  tutor/part2.html
AK>  also there is a (much more involved) example for studing 
AK>  proton transport in bulk water which, however, assumes, that you 
AK>  have some previous experience in classical MD, at
AK>  
AK>  http://www.theochem.ruhr-uni-bochum.de/~axel.kohlmeyer/cpmd-intro.html
AK>  
AK>  hope this will help you,
AK>  	axel kohlmeyer.
AK>  
AK>  AK> Thank you very much for your kind attention.
AK>  AK> 
AK>  AK> 
AK>  AK> Rgds,
AK>  AK> Adrian.
AK>  AK> 
AK>  
AK>  -- 
AK>  
AK>  
AK>  =======================================================================
AK>  Dr. Axel Kohlmeyer                        e-mail: axel.kohlmeyer at rub.de
AK>  Lehrstuhl fuer Theoretische Chemie          Phone: ++49 (0)234/32-26673
AK>  Ruhr-Universitaet Bochum - NC 03/53         Fax:   ++49 (0)234/32-14045
AK>  D-44780 Bochum  http://www.theochem.ruhr-uni-bochum.de/~axel.kohlmeyer/
AK>  =======================================================================
AK>  
AK>  
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AK> 

-- 


=======================================================================
Dr. Axel Kohlmeyer                        e-mail: axel.kohlmeyer at rub.de
Lehrstuhl fuer Theoretische Chemie          Phone: ++49 (0)234/32-26673
Ruhr-Universitaet Bochum - NC 03/53         Fax:   ++49 (0)234/32-14045
D-44780 Bochum  http://www.theochem.ruhr-uni-bochum.de/~axel.kohlmeyer/
=======================================================================