Now I am really confused. I am accustomed to being able to change from the login shell, which in the case of my 9.3 installation is the bash shell, to the C shell by entering csh in a terminal. Suddenly, if I try that I get an error message: computation@abnormal:~/CompChem/nwchem-4.7> csh /usr/bin/.: Permission denied. (csh is linked to tcsh in /usr/bin and invokes the same error message) Yet, I have a number of programs that run in the C shell. I just tried to run one of them, ecce, and it still works. I have written a script that starts the server: #!/bin/csh /home/computation/ecce-v3.2.2/server/ecce-utils/start_ecce_server So apparently the script will evoke the C shell. If I change to root I can switch to the C shell. How can I, once again, accomplish this as a user? Thanks in advance. -- Stephen P. Molnar, Ph.D. Life is a fuzzy set Foundation for Chemistry Stochastic and multivariant http://www.geocities.com/FoundationForChemistry