Re: [Jmol-users] FW: FW: change cell parameters

[Robert H. <ha...@st...>]

On Thu, Nov 11, 2010 at 9:30 AM, pieremanuele canepa <pc...@ke...>wrote:

> Yes you leave the atoms in their positions rebuilding the cell around. Of
> course  the symmetry is lost. This is the price the user has to pay.
>
>
So, you mean, just giving them different fractional coordinates. They are
stored as Cartesian coordinates anyway, so this should not be a particular
problem.

Q: Would it be for the current model only, or for all models? How would we
decide that? Perhaps by previously selecting the atoms it would apply to?

Q: We would not necessarily have to remove all the space group info. Of
course, doing this might wreck that. Symmetry is not an aspect of the unit
cell, per se, but of the model itself. Is there some reason you feel we
would have to remove symmetry operators?

Q: It seems to me the only benefit of this is that you get to use different
fractional coordinates. Do you see anything else that would be beneficial?



> It would be interesting especially if you want to to run cluster type
> systems within PWs codes.


I have no idea what that means, sorry!


> Or if you want to extract a cluster from a periodic system.
>
>
What's extracting anything from the model have to do with it? Can't you do
that already?

Bob

-- 
Robert M. Hanson
Professor of Chemistry
St. Olaf College
1520 St. Olaf Ave.
Northfield, MN 55057
http://www.stolaf.edu/people/hansonr
phone: 507-786-3107


If nature does not answer first what we want,
it is better to take what answer we get.

-- Josiah Willard Gibbs, Lecture XXX, Monday, February 5, 1900