STRUCTURE, ENERGETICS, AND THERMODYNAMICS OF HYDROGEN BONDED MOLECULAR CLUSTERS

关于氢键相互作用的重要性，我们可以学到很多 在生物系统中从与结构相关的研究中获得能量 以及分子团簇的热力学性质。由于 集群研究中遇到的实验困难，计算机 模拟已经成为理论上的一个强有力的工具 此类系统的描述。基于此，我们建议研究 几种氢键分子簇的结构和能量学 通过模拟退火法。在描述了 这些团簇的势能面、热力学性质 将使用经典和量子蒙特卡罗技术来获得。 与经典蒙特卡罗方法不同，量子蒙特卡罗方法 是完全量子力学的，所以振动自由度， 非谐性和隧道效应将被正确和严格地纠正 同时进行治疗。这项研究将严格地包括量子 分子团簇热力学性质的影响 具有真实的粒子间势能。与此同时，它将 介绍计算机模拟的几个重要方面，例如适当 组态空间采样与量子热力学的收敛 总体平均值。要考虑的分子团簇是 之所以选择它们，是因为它们在生物活跃的地区 大分子系统。因此，理论上的描述将 有助于理解分子间的相互作用 大分子系统的特定区域。

Much can be learned about the importance of hydrogen bond interactions in biological systems from studies related to the structure, energetic and thermodynamic properties of molecular clusters. Owing to the experimental difficulties encountered in cluster studies, computer simulations have emerged as a powerful tool in the theoretical description of such systems. Based on this, we propose to study the structure and energetics of several hydrogen bonded molecular clusters by means of simulated annealing procedures. After characterizing the potential energy surface for these clusters, thermodynamic properties will be obtained using both classical and quantum Monte Carlo techniques. Unlike Classical Monte Carlo methods, the Quantum Monte Carlo approach is fully quantum mechanical so that the vibrational degrees of freedom, anharmonicities and tunneling effects will be correctly and rigorously treated simultaneously. This study will rigorously include quantum effects in the thermodynamic properties of molecular clusters described with realistic interparticle potentials. At the same time, it will address several important aspects of computer simulations such as proper sampling of configuration space and convergence of quantum thermodynamic ensemble averages. The molecular clusters to be considered have been chosen because of their importance in biologically active regions of macromolecular systems. Hence, the theoretical description will contribute to the understanding of intermolecular interactions in specific regions of macromolecular systems.