A Peaceman-Rachford Splitting Method for the Protein Side-Chain Positioning Problem

Abstract: We formulate a doubly nonnegative (DNN) relaxation of the protein side-chain positioning (SCP) problem. We inherit the natural splitting of variables that stems from the facial reduction technique in the semidefinite relaxation. We solve the relaxation using a variant of the Peaceman-Rachford splitting method. Our numerical experiments show that we solve almost all instances of the NP-hard SCP problem to optimality.