Computational methods inspired by Tsallis statistics: Monte Carlo and molecular dynamics algorithms for the simulation of classical and quantum systems
Je. Straub et I. Andricioaei, Computational methods inspired by Tsallis statistics: Monte Carlo and molecular dynamics algorithms for the simulation of classical and quantum systems, BRAZ J PHYS, 29(1), 1999, pp. 179-186
Tsallis's generalization of statistical mechanics is summarized. A modifica
tion of this formalism which employs a normalized expression of the q-expec
tation value for the computation of equilibrium averages is reviewed for th
e cases of pure Tsallis statistics and Maxwell-Tsallis statistic, Monte Car
lo and Molecular Dynamics algorithms which sample the Tsallis statistical d
istributions are presented, These methods have been found to be effective i
n the computation of equilibrium averages and isolation of low lying energy
minima for low temperature atomic clusters, spin systems, and biomolecules
. A phase space coordinate transformation is proposed which connects the st
andard Cartesian positions and momenta with a set of positions and moments
which depend on the potential energy. It is shown that pure Tsallis statist
ical averages in this transformed phase space result in the q-expectation a
verages of Maxwell-Tsallis statistics. Finally, an alternative novel deriva
tion of the Tsallis statistical distribution is presented. The derivation b
egins with the classical density matrix, rather than the Gibbs entropy form
ula, but arrives at. the standard distributions of Tsallis statistics, The
result suggests a new formulation of imaginary time path integrals which ma
y lead to an improvement in the simulation of equilibrium quantum statistic
al averages.