Statistical thermodynamics of hindered rotation from computer simulations

Due to the nonlinearity of internal molecular coordinate space, comprehensi ve statistical mechanical treatment of polyatomic molecules presents a form idable theoretical problem where traditional statistics does not hold. Here we introduce a new theoretical approach to the hindered internal rotor pro blem, which relies on simulated statistics of microstates, rather than on f irst-principles calculations of the partition function. The concept links t raditional statistical-mechanical thermodynamics to an authentic treatment of curvilinear descriptive statistics. The results are illustrated by class ical molecular dynamics simulations.