[xcrysden] Re: Question on XCrysden

[Tone Kokalj]

On Fri, 2005-07-22 at 16:16 -0400, gunnkim@chips.ncsu.edu wrote:
>
> I want to know how to plot the charge density difference of two systems.
> For example, one is an isolated benzene molecule and the other is under
> the homogeneous electric fiels of 0.3 V/A.
> I need to express the electric polarization by the difference of the total
> charge densities of both systems.
> 
> Can I make the picture using XCrysden program?

Yes, you can. First, you will need to construct a proper XSF file, where
both densities will be specified. You can read how to do it here:

http://www.xcrysden.org/doc/XSF.html#__toc__11

When the XSF file is constructed, you load it as: xcrysden --xsf
file.xsf

Then choose the menu: Tools->Data-Grid. A window will pop-up. Select the
two datagrids. For the first set the "multiply" factor of 1.0, while for
the second set it to -1.0. These will subtract the two datagrids, which
is what you need. Click OK and proceed ...

Regards, Tone