title: Thermodynamics of water octamer in a uniform electric field.
abstract: We study the water octamer in a uniform electric field using the all-exchanges parallel tempering Monte Carlo method in the canonical ensemble. The heat capacity, quenched energy configurations, and the order parameter Q(4) are employed to understand the phase changes observed as a function of temperature and the strength of the applied electric field. At a low field strength of 0.1 V A(-1) a solidlike to liquidlike "melting" transition is detected. The corresponding heat capacity peak appears around 206 K, where Q(4) shows a significant change of slope. For E> or =0.5 V A(-1) such features are absent. However, at E=0.5 V A(-1) we find a solidlike to solidlike transition between cubic and extended structures around T approximately 25 K.
authors.affiliation: Departamento de Física Fundamental II, Universidad de La Laguna, 38205 La Laguna, Tenerife, Spain. jhrojas@ull.es
authors.forename: Javier
authors.initials: J
authors.lastname: Hernández-Rojas
authors.forename: Briesta S
authors.initials: BS
authors.lastname: González
authors.forename: Tim
authors.initials: T
authors.lastname: James
authors.forename: David J
authors.initials: DJ
authors.lastname: Wales