title: Explicit factorization of external coordinates in constrained statistical mechanics models.
abstract: If a macromolecule is described by curvilinear coordinates or rigid constraints are imposed, the equilibrium probability density that must be sampled in Monte Carlo simulations includes the determinants of different mass-metric tensors. In this work, the authors explicitly write the determinant of the mass-metric tensor G and of the reduced mass-metric tensor g, for any molecule, general internal coordinates and arbitrary constraints, as a product of two functions; one depending only on the external coordinates that describe the overall translation and rotation of the system, and the other only on the internal coordinates. This work extends previous results in the literature, proving with full generality that one may integrate out the external coordinates and perform Monte Carlo simulations in the internal conformational space of macromolecules.
authors.affiliation: Departamento de Física Teórica, Facultad de Ciencias, Universidad de Zaragoza, Pedro Cerbuna 12, 50009, Zaragoza, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Echenique
authors.forename: Iván
authors.initials: I
authors.lastname: Calvo
mesh_terms: D003198:Computer Simulation; D008956:Models, Chemical; D009010:Monte Carlo Method