[CPMD-list] CPMD Exercises

[Axel Kohlmeyer]

On Wed, 12 May 2004 kohsj at ihpc.a-star.edu.sg wrote:

AK> Dear Prof Hutter,

dear adrian,

although i am not prof. hutter <g>, i hope i can provide 
the answers you need.

AK> I'm currently trying out the exercises listed on your website.  I'm on
AK> practice for the h2 molecule.  My questions are as follows:
AK> 
AK> 1.     What does it mean by the keyword "NEWCODE" under section &DFT?

there a two implementations of the functionals in CPMD. this activates
the newer one (which is also the default and recommended). this is
featured in the manual, but at the _end_ of the list of keywords.


AK> 2.  What do the contents under section &ATOMS refer to?  They couldn't
AK> be found anywhere in the manuals.

the format of the &ATOMS section _is_ explained in the manual. just
look under 'Further details of the input'.

AK> 3.  Also, I realized that there was a section in the Appendix
AK> explaining the generation of pseudopotentials for this set of
AK> practice.  Where and how will these be used?

you can take the pseudopotentials you need from the pseudopotential
library in the CPMD dowload section. if you want to create 
pseudopotentials for CPMD yourself (not recommended if you are a 
beginner) or learn some more about their properties and derivation, 
then you can for example have a look at the documention provided
with paolo gianozzi's pseudopotential code. 
<http://www.nest.sns.it/~giannozz/software.html>


AK> 4.  A general question... What are the most basic sections and
AK> keywords we need to use in creating an input file?  How are the
AK> pseudopotentials referred to in the input file?

you need the sections &CPMD, &DFT, &SYSTEM, and &ATOMS.
the syntax of pseudopotential specification is discussed 
in the manual.

as for the h2-example. some weeks ago, i started working on a
real cpmd-tutorial starting with the material from juerg hutters
homepage. since i can only work on it in my (currently very 
sparse) free time, there is very little there yet (basically only 
the h2 wavefunction optimization and the and a discussion of the 
input and output). also it has not been reviewed by anybody, 
so there are likely to be many errors or omissions.

if this doesn't scare you, you can still have a peek at it at:
http://www.theochem.ruhr-uni-bochum.de/~axel.kohlmeyer/cpmd-tutor/part2.html

also there is a (much more involved) example for studing 
proton transport in bulk water which, however, assumes, that you 
have some previous experience in classical MD, at

http://www.theochem.ruhr-uni-bochum.de/~axel.kohlmeyer/cpmd-intro.html

hope this will help you,
	axel kohlmeyer.

AK> Thank you very much for your kind attention.
AK> 
AK> 
AK> Rgds,
AK> Adrian.
AK> 

-- 


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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/
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