Command Not Found

If you get the error message Command not found on Linux when trying to run quantumatk or atkpython from a terminal window after installing QuantumATK, then first of all try to close the terminal window and open a new one; this is needed for changes to the PATH variable to take effect. If the problem persists, there are primarily two possibilities:

  • QuantumATK was installed by a different user, e.g. root. In this case you must set up the PATH manually to include the <quantumatk_installation_path>/bin directory.

  • If you are using tcsh (or any other shell than Bash), you must also manually define the PATH` in .tcshrc (or similar for your particular shell). Type echo $SHELL to find out which shell you are using.

In both cases you need to restart the terminal for the changes to take effect. Check that the relevant QuantumATK directories are in your PATH by typing echo $PATH.

The same can happen on Windows as well, with a different error message:

'quantumatk' is not recognized as an internal or external command, operable program or batch file.

The solution is equivalent, one can manually add the <quantumatk_installation_path>/bin directory in the user PATH environment variable, then start a new shell.