Created in RasMol 2.7.2.1.1 using diamond.pdb and the following commands:

GUI options were: Options->Specular, Display->Ball & Stick

Then, in the command line:

background white
color grey
write diamond-000.gif
set write true
script script.txt

where script.txt was a separate text file in the same directory, consisting of the same two repeating lines:

rotate y 03
write diamond-001.gif
rotate y 03
write diamond-002.gif
rotate y 03
write diamond-003.gif
...

from 001 up to 119 (for a total of 120 images when combined with diamond-000.gif).

This was then loaded in Adobe ImageReady, cropped to dimensions divisible by 8 (264x192), exported as this animated GIF, which was then converted to an Ogg Theora video with the ffmpeg2theora command: