The Ansys Forte environment must be set up before execution.
To set up the environment on Windows, from a DOS prompt run the run_forte_env_setup.bat file located in the installation bin directory:
> call "C:\\Program Files\ANSYS Inc\v242\reaction\forte.win64\bin\run_forte_env_setup.bat"
To set up the environment on Linux (csh and tcsh users), from a terminal source the forte_setup.sh file located in the installation bin directory:
> source $HOME/ansys_inc/v242/reaction/forte.linuxx8664/bin/forte_setup.sh
> . $HOME/ansys_inc/v242/reaction/forte.linuxx8664/bin/forte_setup.ksh
Note: The instructions above assume that you have installed Ansys Forte in your Linux home directory. If you have installed into a different location, replace "$HOME" in the above instructions with the actual (absolute) path to your installation.