Q. I think I found a bug in CASTEP. What should I do?
A. First check whether anybody else has seen the behaviour. A searchable CASTEP bug database is available at CCPforge. You can also ask on the mailing list.
You may enter a new bug report at CCPforge. Please try to include a minimal set of input files to demonstrate the problem if at all possible, a description of the steps needed to reproduce the problem, and a statement of both what result you expected and what you observed.