Programs for the IBM Parallel Environment for AIX must be compiled with the current release of the compiler you are using (such as mpxlf,mpcc, or mpCC). If the command you're trying to use cannot be found, make sure the installation was successful and that your PATH environment variable contains the path to the compiler scripts. These commands call the Fortran, C, and C++ compilers respectively, so you also need to make sure that the underlying compiler is installed and accessible. Your System Administrator or local AIX guru should be able to assist you in verifying these things.