Free energy calculations long range forces

Tlierc are two major sources of error associated with the calculation of free energies fi computer simulations. Errors may arise from inaccuracies in the Hamiltonian, be it potential model chosen or its implementation (the treatment of long-range forces, e j lie second source of error arises from an insufficient sampling of phase space. 

Two theoretical force curves calculated by using Eqs (25) and (26) are shown in Fig. 18. In these calculations we used a Kelvin radius of 320 nm and an interfacial tension difference of 3.3 mN/m. The measured force curves fall in between the extreme cases of full equilibrium, where the volume of the condensate is changing with distance to minimize the free energy, and the case of no change in condensate volume with separation. Long-range forces due to capillary condensation have been observed previously by Petrov et al. who foimd that water condensed between two surfaces immersed in a microemulsion. (83). Capillary condensation of sparingly soluble surfactants between surfaces close to each other in surfactant solutions has also been reported (84). 

Free Energy Perturbation Calculations Molecular Dynamics and Hybrid Monte Carlo in Systems with Multiple Time Scales and Long-range Forces Reference System Propagator Algorithms Molecular Dynamics DNA Molecular Dynamics Simulations of Nucleic Acids Molecular Dynamics Studies of Lipid Bilayers. 

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