[Chimera-users] Measuring SASA of ligand

I’m dealing with two separate trajectories involving: 1. Ligand A in complex with the monomeric subunit of a given protein A 2. the same ligand in complex with the dimer of protein A I would like to measure the buried (or solvent accessible) surface area of ligand A in both cases. I referred to a relevant posting in the list (http://www.cgl.ucsf.edu/pipermail/chimera-users/2016-June/012472.html) but I’m not sure how this could apply in the above case. I’d be grateful for any suggestion on how to deal with this type of measurement. Many thanks in advance for any suggestions George