There is no ‘compute omega’ command in LAMMPS.
What is computed by ‘compute omega/chunk’ is described in the documentation for that command.
Interpretation of the data is not the job of the LAMMPS developers, but that of the user. If you feel insecure, you should apply the scientific method to get insight (i.e. formulate a hypothesis, set up some simple tests that would either confirm or conflict with the hypothesis, observe the results and either repeat with a modified hypothesis or stop).