[ase-users] atoms object with asap calculator

[Jakob Schiøtz]

Dear Tom,

Asap supports the Effective Medium Theory model for atomic interaction.  It is a simplified interatomic potential that give a good description of the interaction between late transition metals with an almost full d-shell (columns 10 and 11 in the periodic table).  It does not give a reasonable description of molecules.  For molecules, you probably need a DFT based program, or for a description at a similar level of accuracy as EMT you could use one of the chemistry "force fields".  They are not supported in our software, with the exception of the Brenner potential for Carbon and hydrocarbons, which is implemented in Asap.

Sorry that I cannot be more helpful

Best regards

Jakob Schiøtz


On 22 Sep, 2011, at 21:56, Tom Haxton wrote:

> Hi,
> I would like to define a molecule with the atoms object and calculate energies using asap.  I haven't found any examples on how to do that.  I try:
> 
> #/usr/bin/python
> from asap3 import Atoms, EMT
> d = 1.1
> co = Atoms('CO', positions=[(0, 0, 0), (0, 0, d)])
> co.set_calculator(EMT())
> 
> but I get the error 
> 
> Traceback (most recent call last):
>   File "co.py", line 9, in <module>
>     co.set_calculator(EMT())
>   File "/opt/ase/3.5.1/lib/python2.6/site-packages/ase/atoms.py", line 206, in set_calculator
>     calc.set_atoms(self)
> asapserial3.AsapError: This element isn't defined in EMT.
> 
> Note that the analogous code in ase works fine:
> 
> #/usr/bin/python
> from ase import Atoms
> from ase.calculators.emt import EMT
> d = 1.1
> co = Atoms('CO', positions=[(0, 0, 0), (0, 0, d)])
> co.set_calculator(EMT())
> 
> Can anyone suggest what I should do?  Thank you very much!
> 
> Best,
> Tom
> 
> 
> <ATT00001.c>

--
Jakob Schiøtz, Ph.D.
Associate professor (lektor)
Program coordinator, M.Sc. in Physics and Nanotechnology
(kandidatstudieleder, Fysik og Nanoteknologi)
CINF, Department of Physics
Technical University of Denmark
DK-2800 Kongens Lyngby, Denmark
http://www.cinf.dtu.dk/~schiotz/