# cpmd.x file.in [PP_path] 
file.out
Running cpmd.x requires the following files:
- an input file file.in (see section 11)
- pseudopotential files for all atomic species specified
in file.in (see section 11.5.1).
The path to the pseudopotential library can be given in different ways:
- The second command line argument PP_path is set.
- If the second command line argument is not given, the program checks
the environment variables
CPMD_PP_LIBRARY_PATH and PP_LIBRARY_PATH, respectively.
- If neither the environment variables nor the second command line argument are set,
the program assumes that the pseudopotential files are in the current directory
During the run cpmd.x creates different outputs. Various status messages to monitor the correct operation of the program is printed to standard output (in our example redirected to the file file.out). In addition data is written into different files (depending on the keywords specified in the input file.in). An overview is given in section 12. Large files are written either to the current directory, the directory specified by the environment variable CPMD_FILEPATH, or a directory specified in the input file using the keyword FILEPATH.
Jobs can be stopped at the next break point by creating a file named EXIT in the current run-directory of the CPMD executable.