[chimera-dev] Different models

Hi there, i have a question concerning a kind of extension, i'm considering ... I'm a PhD student using chimera for the depiction and comparison of chemical and protein structures. I'm wondering if i could implement an extension that would allow me a self-defined type of molecule model, where the atoms are replaced by self-defined centers representing specific functional groups in a molecule. Could you give me a hint, how to do that? I mean, what kind of class do i have to change in order to define such a model and to load a corresponding file type? Thanks in advance, Marco Mernberger