Visualization of Crystal Structures
Several technologies exist for the visualization of 3-D crystal structures using a web browser.
Quicktime VR is an interactive movie format that can be used to allow the reader some control over image view. CrystalMaker is a commercial crystal structure viewing software package that includes the option of creating a Quicktime VR movie of the structure. This is easily done in a few minutes by a user with no prior experience with Quicktime VR. Simply follow the instructions in the CrystalMaker package. To see the Quicktime VR file, a viewer must have a copy of the Quicktime Plugin for their browser that is available free from Apple for both Macintosh and PC platforms at http://www.apple.com/quicktime/download/.
An example, created using CrystalMaker, of a diopside structure image that can be rotated about a horizontal axis is shown here. Place your mouse on the image and drag it down then up to see the structure in different orientations. You can enlarge the image by holding down the shift key. Shrink the image by holding down the Control key.
One technology that is popular among chemists uses the Chime browser plug-in, which is available for free from MDL Information Systems, Inc. at http://www.mdlchime.com/chime/.
Chime works best in Netscape, but may also work in Internet Explorer depending on your configuration. You will have to register by supplying an e-mail address, but once that is done, you have access to the Chime plug-in, tutorials and other useful information about Chime. If you have the Chime plug-in and are using Netscape, you should be able to see the diamond and graphite structures below.
The viewer can change the view with the mouse. On the PC, right click, and on the Mac, click and hold for options. To zoom, click and drag the mouse with the shift key down.
Creating web sites with Chime images is simple, as the following example demonstrates:
<HTML> <HEAD> <TITLE>Chime example</TITLE> </HEAD> <BODY BGCOLOR="#ffffff"> <P><EMBED SRC="diamond.pdb" display3d="Ball&Stick" WIDTH="300" HEIGHT="300" ALIGN="BOTTOM" BGCOLOR="#000000" startspin="true" spiny="10" spinz="20" spinx="15"><!--/SELECTION--> </BODY> </HTML>
The file containing the molecular structure is diamond.pdb. There are a number of other switches that can be set to control how the image appears on the screen. Once the browser plug-in is installed in the plug-in folder, 3-D crystal structures can be viewed in a browser window.
There is a considerable amount of information on the web about creating Chime compatible images. Most of the Chime molecules we've encountered are organic molecules, but there are some sites with inorganic crystals. These sites will provide a good starting point:
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