From: Douglas Houston (
Date: Fri Oct 31 2014 - 11:05:24 CDT

Hi all,

Does anyone know of any software that can do 'real-time' orbital rendering?

What I'm looking for specifically is a way to visualise electron
density (including how it changes in response to e.g. van der Waals
influences), for teaching and for structure-based ligand design
purposes. It would be a way for the user to see e.g. induced
dipole-dipoles being set up as they move two molecules closer
together, etc. Appearance-wise, in my mind's eye the density is just
that; something like a "volumetric fog" effect, which is already
implemented in OpenGL and DirectX:

A few conceptual examples:

I guess it would need some way of parsing the output of the
(GPU-accelerated, presumably) MO calculator into GPU API commands?

Would expecting to be able to see real-time shifts in density as the
user interactively moved atoms/molecules around be reasonable? Or is
that still too computationally expensive?

I think there are people already working on something like this idea
for VMD - what stage is it at?


Dr. Douglas R. Houston
Institute of Structural and Molecular Biology
Room 3.23, Michael Swann Building
King's Buildings
University of Edinburgh
Edinburgh, EH9 3JR, UK
Tel. 0131 650 7358

The University of Edinburgh is a charitable body, registered in
Scotland, with registration number SC005336.