>Does anyone know a free program capable of overlaying crystal structures?
The only program I am aware of that can do this graphically is CrystMol http://www.crystmol.com/features.html - Structure overlay and comparison. It is not free but the cost is reasonable. I would be interested to hear of other programs that can do this graphically as well as give numerical output. Lachlan ----------------------- Lachlan M. D. Cranswick Contact outside working hours / Coordonnees en dehors des heures de travail: NEW E-mail / courriel: lc *at* bluehaze.com.au Home Tel: (613) 584-4226 ; Cell/mobile: (613) 401-6254 WWW: http://lachlan.bluehaze.com.au/ P.O. Box 2057, Deep River, Ontario, Canada, K0J 1P0 (please use clear titles in any Email - otherwise messages might accidentally get put in the SPAM list due to large amount of junk Email being received. If you don't get an expected reply to any messages, please try again.) (Essayez d'utiliser des titres explicites - sans quoi vos messages pourraient aboutir dans un dossier de rebuts, du fait de la quantite tres importante de pourriels recue. Si vous n'obtenez pas la reponse attendue, merci de bien vouloir renvoyer un message.)