Mapping the Finite-Temperature Behavior of Conformations to Their Potential Energy Barriers: Case Studies on Si₆B and Si₅B Clusters

Abstract

Dynamical simulations of molecules and materials have been the route to understand the rearrangement of atoms within them at different temperatures. Born–Oppenheimer molecular dynamical simulations have further helped to comprehend the reaction dynamics at various finite temperatures. We take a case study of Si6B and Si5B clusters and demonstrate that their finite-temperature behavior is rather mapped to the potential energy surface. The study further brings forth the fact that an accurate description of the dynamics is rather coupled with the accuracy of the method in defining the potential energy surface. A more precise potential energy surface generated through the coupled cluster method is finally used to identify the most accurate description of the potential energy surface and the interconnected finite-temperature behavior.

Pd8 Cluster: Too Small to Melt? A BOMD Study

“…For instance, the works by Schön et al Doye and Wales, Heiles and Johnston, and Lourenço et al are inspiring examples that have employed empirical and ab initio schemes to perform extensive global optimization searches to locate the different minima of a PES. Most interestingly, recent experimental and theoretical studies have shed some light on the structural stability of the located minimum-energy structures through the analysis of the energy barriers among the different isomer structures. − Foster et al determined the energy difference between isomers of gold nanoparticles at low (20–125 °C) and high (125–500 °C) temperatures, in both cases observing cluster structural rearrangements between different symmetries. Maneri et al performed BOMD simulations at finite temperatures to analyze the thermal stability of small Si–B clusters, while Fisicaro et al have discussed the principles underlying the structural stability of metal clusters, identifying that these clusters find their ground state by crossing low energy barriers.…”

“…Furthermore, at this size, EPs fail to predict the correct structure because the decisive quantum variables needed are not explicit in the analytical form of the EP. In this regard, considerable advances in the AIMD methods have been achieved with the aim of studying transition and noble metal clusters ,,,,− employing the more advanced AIMD methods. Successful applications of the BOMD method are described by Calaminici et al employing the auxiliary density functional theory (ADFT) scheme implemented in the deMon2k package .…”

Understanding the Stability of an Unprecedented Si–Be Bond within Quantum Confinement

“…34−36 At the quantum confinement phase space, it has been one of the most widely studied systems both experimentally as well as computationally. [36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54]68,69 While, experimentally, Si has been evidenced to bond with several main group elements such as boron, carbon, nitrogen, oxygen, etc., a bond with the Be atom is one of the most unprecedented ones so far. While its high ionization potentials and small size result in Be forming covalent bonds with many elements, B−Si bonds are quite rare.…”

“…Silicon, being the earth’s most abundant element, has not been left behind in this context and has been reported to participate in distinctive or multiple bonding with itself as well as with other heavier elements. − At the quantum confinement phase space, it has been one of the most widely studied systems both experimentally as well as computationally. − ,, While, experimentally, Si has been evidenced to bond with several main group elements such as boron, carbon, nitrogen, oxygen, etc., a bond with the Be atom is one of the most unprecedented ones so far. While its high ionization potentials and small size result in Be forming covalent bonds with many elements, B–Si bonds are quite rare.…”