MDL Chime

MDL Chime  is a free plugin used by web browsers to display the three dimensional structures of molecules. It is part of the ISIS product line acquired by Symyx Technologies from scientific publisher Elsevier in October 2007. It is based on the RasMol code.

Chime is used by a wide range of biochemistry web sites for the visualization of macromolecules. Many of these sites are linked to the World Index of Molecular Visualization Resources MolVisIndex.Org. Chime was also used until 2006 at the Protein Data Bank to examine structures stored there.

Although available in 1998 in both Windows 98 and Mac OS 9 versions for both Netscape and Internet Explorer browsers, development of Chime did not follow the move to Mac OS X for the Mac and support for Windows-based browsers other than Internet Explorer was dropped (although it works well in Mozilla Firefox). No significant features have been added since 1998 except for updates in the installation package to follow the development of Windows and Internet Explorer.

Chime may be superseded by Jmol, but the current market share and trends are unclear. Jmol is a non-proprietary Java molecular visualization application/applet that has maintained most Chime command compatibility while adding features.

Two features of Chime which are not yet reproduced with Jmol:


 * 'Sculpt' mode: The ability to change the conformation of molecules in a realistic way by dragging their atoms to new positions. This is a useful feature for exploring the conformational possibilities of a molecule such as the inability to rotate a carbon-carbon double bond.


 * Calculating and drawing molecular surfaces coloured according to electrostatic or hydrophobic potential. Chime can calculate these surfaces for any molecule.