[Chimera-users] SASA vs. MSA

Hi all, I was wondering if you could help me conceptualize what is going on in this situation. I ran both solvent accessible surface area and solvent excluded (molecular) surface area calculations. When I compared the output for both of these calculations I found that, overall, atoms that contribute to the SASA are buried 1-3 angstroms deeper in the protein than those that contribute to the MSA. I don't really understand how this could be unless the deeper buried SASA atoms have a much larger van der waals radii than MSA atoms (I get that some atoms contribute to both). Thanks!