You must add these lines to your .cshrc file. This example is for SGI, but it is not difficult to modify it for other platforms.
In any case, do not forget to alter the paths (
displayed in red) to point at the proper location on your system.

#----------- CHECK WHERE WE HAVE LOGGED IN ------------- # and set default path for AMBER and CHARMm #-------------------------------------------------------   switch (`uname -a | awk '{ print substr($0,1,4) }'`)   case "IRIX": setenv CHARMHOME /disk11/local/ProServer/Charmm setenv AMHOME /usr/bioinf/bin/OM/AMBER setenv amber /usr/bioinf/bin/OM/AMBER/amber41 setenv pamber /usr/bioinf/bin/OM/AMBER/amber41/parallel_exe switch (`hinv | grep 'CPU:' | awk '{print $3}'`) case "R4400" set path = ($amber/mips2_exe $path) echo "CPU: R4400" breaksw case "R10000" set path = ($amber/mips4_exe $path) echo "CPU: R10000" # --- check if we can run the parallel version set nbproc = `hinv | grep MHZ` if (`echo $nbproc | awk '{print $3}'` == "MHZ") then set nb = `echo $nbproc | awk '{print $1}'` if ($nb > 1) then echo $nb processors alias psander '$pamber/sander' alias pgibbs '$pamber/gibbs' endif endif breaksw   default: echo "CPU: unknown (by script!)" breaksw   default: breaksw   endsw