[CPMD-list] Repl; What is differences between metadynamics and transition path sampling

[Titus Van Erp]

for CPMD?
References: <200712031141317344566 at sina.com>
In-Reply-To: <200712031141317344566 at sina.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 8bit
User-Agent: Internet Messaging Program (IMP) 3.2-cvs
X-Originating-IP: 10.33.107.5

Hi K. Dong,

The difference is that these are very different methods. They are both
rare event methods which allow to overcome high reaction barriers, but
they compute different properties. Metadynamics
can be used to calculate free energy surfaces but its dynamics is in
principle purely artificial. TPS is a way to compute true dynamical path
ways from a reactant state to a product state and to determine rates.

I am not aware how metadynamics is used in CPMD, but for path sampling,
the present status is that everyone uses their own written code. I have
written a code for Transition Interface Sampling, which is a more
efficient version of TPS, but this code is still in the developing status. 

Available codes are the Geissler code (TPS with cpmd interface) at
http://www.science.uva.nl/~bolhuis/tps/download.html and the Moroni code
at http://www.science.uva.nl/~moroni/IS/index.html (cpmd interface needs
to be added). But these codes would both need revisions to be applicable
for specific use and not too much documentation is available unfortunately.

sincerely
Titus van Erp


Quoting kdong <kdong_bj at sina.com>:

> Hi everyone,
>   
> What is differences between metadynamics and transition path sampling
> for CPMD?
> 
> How to communicate both code or how to write a input to transition
> path samping using CPMD trajectories?
> 
> Best Regards
> 
> k.dong
> 
> 2007-12-03 
> 
> 
> 
> kdong 
> 


-- 
Titus van Erp
Centre for Surface Chemistry and Catalysis
Catholic University of Leuven
Kasteelpark Arenberg 23
B-3001 Heverlee (Leuven), Belgium
K.U.Leuven postbus 2461-COK/LAB VOOR COLLOIDCHEMIE
Tel: + 32 (0)16 32 1591
Fax: + 32 (0)16 32 1998
 

Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm