I am currently employing ChimeraX to study features of a molecule. I am studying ribosomal RNA (rRNA) in the E. coli ribosome using the PDB model 4YBB. We are interested in seeing what residues from the 23S rRNA are solvent-accessible using a probe radius of 3Å. We are wondering if you could give us some advice on how to achieve this. We have tried a few methods we have found online, but they all yield different results. 

I look forward to hearing from you. Thank you very much in advance.

Best,