Generalized coordinate hybrid Monte Carlo

Abstract
We describe a novel hybrid Monte Carlo algorithm for the off-lattice simulation of dense, atomistically detailed polymer systems. Bond lengths and bond angles are constrained to their equilibrium values and a generalized-coordinate description using the torsional degrees of freedom is employed. Simple, decoupled, Cartesian-like equations of motion are obtained by the introduction of fictitious angular momenta variables conjugate to the torsional degrees of freedom. A unique time scale, and hence a mapping onto real time, can be obtained by allocating time-independent, effective moments of inertia to each angular momentum variable.