Free-energy reconstruction from experiments performed under different biasing programs

Recently developed nonequilibrium statistical physics relationships, including Jarzynski’s equality and the Crooks fluctuation theorem, have been used to calculate equilibrium thermodynamic properties using data from both laboratory and computational experiments. Although Jarzynski’s derivation does not include an explicit time dependency, prior work utilizing the relationship to reconstruct free-energy surfaces has combined data from experiments performed under identical conditions. Here, a formalism is developed for combining data from a variety of biasing protocols, as in dynamic force spectroscopy experiments. The method is then demonstrated on data from simulations conducted under a wide range of pulling velocities and with a random biasing protocol.