Displaying electronic structure in OpenDX

Electronic structure codes such as VASP, CASTEP, SIESTA and Conquest produce large amounts of data (such as wavefunctions and charge densities) which need to be visualised. I've been playing around with OpenDX (a freely available and rather powerful visualisation tool) and have created some conversion tools and OpenDX networks to view ball-and-stick models of the atomic structure along with isosurfaces and contour plots (in a given plane) of charge density. I've put together this page so that other people can use these tools.

So far the various tools only work for orthorhombic cells

Basic use instructions:

• Download the tarball
• Unpack it (gunzip ChdensDX.tgz; tar xvf ChdensDX.tar)
• Build the conversion program (gcc -o convertCHG convertCHG.c -lm)
• Create an atomic information file: first line gives number of species, subsequent lines give species number, element and Wigner-Seitz radius in Angstroms (grep RWIG POTCAR will give you this)
• Convert a CHGCAR file from VASP (./convertCHG CHGCAR test 0)
• Fire up OpenDX: dx
• Load a network (Run visual program) - say IsosurfaceAndAtoms.net
• It will complain about a lack of files - this is because you have to give them
• Find the control panel window "Overall Control"
• Enter the charge and XYZ files in the two dialog boxes: test.dx and testXYZ.dx
• Important You need to put the file name.dx not nameCHG.dx into the Charge Density dialog box
• Enjoy the show !

This page will be updated from time to time with further instructions etc. In the mean time, if you need more help, please contact me.

I have created a simple example for bulk silicon here. You can find all the relevant input and output files there, along with a brief description of how I got the image.

Here are some examples:

An isosurface of charge

A contour plot of charge in a particular plane