[Chimera-users] calculate buried surface area

Friends, I have a dimer protein (say monomers 1,2). I have calculated the electrostatic potential of monomer 1 using apbs. I used volume viewer to display the electrostatic surface. I see that the elect. surface of one monomer 1, touches the vdw surface of monomer 2 at a contour level of 1. I want to calculate the total surface area of monomer 2 that is exposed/buried within the elec. surface of monomer 1. Is there any simple. If not suggestion how i can do it with a python script perhaps. Thanks, Bala -- C. Balasubramanian