Bayesian statistical modeling of microcanonical melting times at the superheated regime

No hay miniatura disponible
Fecha
2019-02-01
Profesor/a Guía
Facultad/escuela
Idioma
en
Título de la revista
ISSN de la revista
Título del volumen
Editor
Physica A: Statistical Mechanics and its Applications
Nombre de Curso
Licencia CC
Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)
Licencia CC
https://creativecommons.org/licenses/by-nc-nd/4.0/
Resumen
Homogeneous melting of superheated crystals at constant energy is a dynamical process, believed to be triggered by the accumulation of thermal vacancies and their self-diffusion. From microcanonical simulations we know that if an ideal crystal is prepared at a given kinetic energy, it takes a random time tw until the melting mechanism is actually triggered. In this work we have studied in detail the statistics of tw for melting at different energies by performing a large number of Z-method simulations and applying state-of-the-art methods of Bayesian statistical inference. By focusing on a small system size and short-time tail of the distribution function, we show that tw is actually gamma-distributed rather than exponential (as asserted in a previous work), with decreasing probability near tw∼0. We also explicitly incorporate in our model the unavoidable truncation of the distribution function due to the limited total time span of a Z-method simulation. The probabilistic model presented in this work can provide some insight into the dynamical nature of the homogeneous melting process, as well as giving a well-defined practical procedure to incorporate melting times from simulation into the Z-method in order to correct the effect of short simulation times.
Notas
I
Palabras clave
Bayesian, Gamma distribution, Melting, Microcanonical, Waiting times
Citación
Physica A: Statistical Mechanics and its Applications Volume 515, Pages 546 - 557 1 February 2019
DOI
10.1016/j.physa.2018.09.174