Calculating Overlapping Charges: A Chemist's Query

[sphericalCat]

Another daft chemist question:

I'm looking at two charges spread over two overlapping Gaussians. I want the energy of the interaction, so, I take qq'/r and integrate first over one Gaussian then over the other... except for it all goes up the spout, because the charges are overlapping, and there are a lot of r=0.

There's got to be a really easy way round this, which doesn't involve disrupting the continuity of the Gaussians. What is it??

 

[mgb_phys]

The equations you are using are probably for point charges, I'm not sure you can really speak of overlapping charges - overlapping fileds certainly.

 

[marlon]

Another daft chemist question:

I'm looking at two charges spread over two overlapping Gaussians.

What do these Gaussians represent ? Are they the regions where charge can be found or are they charge distributions ? The former seems acceptable, the latter is quite unlikely. Anyhow, one cannot be talking about overlapping charges, so there must be something wrong in your understanding of the problem. Could you elaborate some more on the problem description, please ?

marlon

 

[sphericalCat]

Sorry, sloppy language on my part. We are talking about regions where charge can be found.

What I basically am trying do is to add a repulsive component to a Madelung energy calculation, so I need something to represent ionic cores of finite size.