Hi Ed, I extended the current Chimera DSN6 file reader to handle the BRIX files. The changed files are in chimera/share/VolumeData, specifically fileformats.py and the dsn6/*.py files. Here is a tar file you can extract in chimera/share to update these files. http://www.cgl.ucsf.edu/home/goddard/voldata.tar.gz % cd /usr/local/chimera/share % tar zxf voldata.tar.gz Let me know if you have trouble with it. I have only tested it on the file you gave me. I used BRIX format documentation from the web though and expect it should work with all files. It will be included in the next Chimera release. Tom