(color online) Sampling efficiencies of various states of SW particles with λ = 1.5 using the isobaric GCE-REMC method. (a) Enthalpy distributions (the left axis) of 72 replicas corresponding to the states of 72 replicas in the temperature-enthalpy plane (the right axis) at the pressure close to the critical pressure . The inset gives the details of enthalpy distribution profiles over the enthalpy ranging from −600 to −500. (b) The enthalpy distributions and temperature-enthalpy plane at pressure far from the critical pressure.