Statistical thermodynamics of hindered rotation from computer simulations

Due to the nonlinearity of internal molecular coordinate space, comprehensive statistical mechanical treatment of polyatomic molecules presents a formidable theoretical problem where traditional statistics does not hold. Here we introduce a new theoretical approach to the hindered internal rotor problem, which relies on simulated statistics of microstates, rather than on first-principles calculations of the partition function. The concept links traditional statistical-mechanical thermodynamics to an authentic treatment of curvilinear descriptive statistics. The results are illustrated by classical molecular dynamics simulations.