[ VAL 77 ] J . P . Valleau and S . G . Whitlington , " A Guide to Monte Carlo for Statistical Mechanics : 1 . High Ways " in Statistical Mechanics , Part A . B . J . Berne , ed , Plenum , New York , 1977 , Chap 4 : J . P . Valleau and G . M . Torrie , " A Guide to Monte Carlo Methods for Statistical Mechanics : 2 . By ways " ibid , Chap 5 .