Point Groups and Bravais Lattices

The following modules and image archives are made available for educational purposes:

high resolution (640x480) animated GIF movies of the 32 point groups, using a helical object as general point;
high resolution (120x1200) JPEG images of each point group (essentially the first frame of each of the animated GIF movies);
an archive of Rayshade input files used to generate most of the things above.

The paragraphs below provide more details on each item. If you plan to use any of this stuff, please read the copyright notice.

Animated GIF movies

Since the movies in the point group module are rather small, I have redone them in animated GIF format for display through a browser. They are now 640x480 pixels and contain, depending on the symmetry, anywhere from 12 to 72 frames each. The loop parameter in the Netscape Application Extension Block has been set to 500.

The movies can be downloaded as needed from this page, or the entire gzipped and tarred archive can be downloaded from here (48602312 bytes).

High resolution JPEG images

Another archive...this one contains 32 JPEG files (compressed with quality 100%), one for each point group. The rendering was done at 1200x1200 pixels, and the images in this archive can be printed on a good quality color printer, e.g., on transparencies for classroom use. You can download the archive here (7970148 bytes).

How did I do all this?

All images and individual movie frames were rendered by the Rayshade 4.0 public domain ray tracing package. If you want to create your own movies, perhaps rotating them around a different axis, or making the helices move, or ... (endless possibilities, only limited by the size of your hard drive...) then you can use this archive (32043 bytes) as a starting point. It contains the complete set of Rayshade input files, including the positions of all symmetry elements and all atoms. You are welcome to modify these files, and if you do get a nice result, please let me know about it...

Copyright and Acknowledgment

First the small print:

The following copyright applies to all files in this distribution. Copyright (c) 1998 Marc De Graef All rights reserved. Redistribution and use with or without modification, are permitted provided that the following conditions are met: 1. Redistributions of this archive must retain the above copyright notice, this list of conditions and the following disclaimer. 2. The name of the Author may not be used to endorse or promote products derived from this distribution without specific prior written permission. In particular, commercial use of images produced from this distribution in any form of print is not allowed, unless specific prior written permission has been granted. THIS DISTRIBUTION IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

And now a word about the sponsor:

The development of this program was only possible with financial help from the National Science Foundation (DMR-9501017, Bruce MacDonald program monitor).

I would welcome any kind of feedback about this distribution; in particular, I am looking for answers to the following questions:

In what kind of environent did you use this distribution?
Did you like it?
How would you modify the distribution?
Does this set of files provide you with a better tool to explain point groups?
How many students have used it at your location?
Any other comments?

Feedback can be sent by e-mail to Marc De Graef.