Photoabsorption markers of pressure-induced phase changes in small mercury clusters. A case study on Hg₈

Abstract

Evolution of low-temperature Hg8 absorption spectrum with increased external pressure.

Finite Systems under Pressure: Assessing Volume Definition Models from Parallel-Tempering Monte Carlo Simulations

“…Consequently, there should exist a region on the pressure axis along which a transformation takes place dragging the cluster from the lowenergy regions of the cluster configuration space to more compact structures with smaller volumes. 32,34,45,46,48 The article is organized as follows: in next section we briefly describe the volume models and their variants implemented in the present study, as well as computational details on how to calculate thermodynamic averages from standard NPT PTMC simulations performed for finite molecular systems by incorporating the corresponding volume model dependent corrections. In the Results and Discussion section we focus on NPT PTMC simulations for testing and applying the different types of volume models on specific thermodynamical properties of an "icelike" cluster formed by 12 water molecules and, in particular, to illustrate the volume model implication on cluster structural transitions under medium to high pressures.…”

“…At high pressures, on the other hand, the PV term becomes comparable to the cluster energy, and structures with smaller volume may be favored over those with lower interaction energy. Consequently, there should exist a region on the pressure axis along which a transformation takes place dragging the cluster from the low-energy regions of the cluster configuration space to more compact structures with smaller volumes. ,,,, …”

Thermodynamics of small mercury clusters and the role of electronically excited states: a case study on Hg13

“…The methodology used in the present work closely follows the methods employed in our previous studies on small mercury clusters. 9,10,15 In particular, the methodology used to investigate the pressure and/or temperature induced structural changes in Hg 8 10 has been adopted without any principal modifications. For the reader's convenience, a basic, more or less self-explanatory overview of the methods introduced in the previous studies is provided here.…”

“…For example, in the Hg N clusters, more than one structural isomer is found starting from N = 6 for which two such isomers exist followed by 4, 5, and 14 structural isomers emerging in Hg 7 , Hg 8 , and Hg 9 , respectively. 9 All these structural motifs may come into play as external conditions (temperature and/or pressure) change (see, e.g. , ref.…”

Phase Transitions and Hysteresis for a Simple Model Liquid Crystal by Replica-Exchange Monte Carlo Simulations

“…This method is widely applicable and has been used for a diverse range of system types, such as hard spherocylinders [ 21 ], small mercury clusters [ 22 ], Glutamine Amides [ 23 ], and water confined within nanotubes [ 24 ]. The isothermal-isobaric replica-exchange algorithm inhibits kinetic trapping problems and, as such, can be used to greatly reduce or even eliminate hysteresis.…”