Schematic illustration of ellipsoid criterion.

Abstract

<p>(A) Three dimensional view of a point locating on the ellipsoid constructed from the total loop length and the two foci and . (B) Two dimensional view along through the -axis of the ellipsoid, with and (dark gray). is along -axis, not shown. The maximum side-chain length is denoted as and the distance cut-off of interaction is . The enlarged ellipsoid, which has updated and , is also shown (light gray).</p