Multibaric-multithermal molecular dynamics simulation of alanine dipeptide in explicit water

Multibaric-multithermal (MUBATH) simulation can escape from local-minimum free-energy states, and one can obtain accurate thermodynamic quantities as functions of any temperature and pressure from a single simulation run. We performed a MUBATH molecular dynamics simulation of an alanine dipeptide in explicit water. The MUBATH simulation sampled the states of P-II, C-5, alpha(R), alpha(P), and alpha(L). On the other hand, the conventional isobaric-isothermal simulation was trapped in local-minimum free-energy states and sampled only a few of them. We calculated the partial molar enthalpy and partial molar volume from the MUBATH simulation. Our results were in accord with those from Raman spectroscopy.