There are probably many sites which list conferences related to chemistry, and computational chemistry. Some links that I know are:
http://www.warr.com
http://www.chemie.uni-regensburg.de/~hoh05008/KONFERENZEN/
http://www.ioc.ac.ru/Chemistry/Conf/
jkl@ccl.net
)
about outher links which are worth looking at.