[Chimera-users] center of rotation

I'm returning to chimera after many years away and am quite impressed with the program, save for one issue: rotating about the screen center. My favorite way of viewing structures is for the rotation to be about a center of my choosing, as is common in many graphics programs (e.g. COOT). I would prefer to pick an atom on the screen and have this become the rotation center. Is there a simple way to accomplish this in chimera? A small point perhaps, but one that is frustrating for me....... Bill Montfort