NER: Toward Efficient Design Tools for Molecular Machines: Theoretical Investigations of Nanosystems

0102848 Sohlberg本提案是针对NSE、NSF-0019而收到的。纳米技术承诺只由一个或几个分子构成的工程化设备。在医学、分子尺度电子学以及国防、空间科学和其他极端环境的信息收集方面的应用被设想。分子涡轮机一次抽出一个分子的气体流，微型阀门以前所未有的位置和剂量特异性输送药物，针头规模的计算机磁盘存储信息库，以及用于违禁品检测的极其灵敏的人工嗅觉，所有这些都在理论上是可能的，但首先必须设计这些设备。该计划的最终目标是开发设计工程工具--通过设计为纳米设备提供“配方”，同时培训未来的工程师和科学家开发和应用它们。就宏观机器而言，发展工程模型的起点是众所周知的：牛顿力学定律和麦克斯韦电磁定律。对于分子系统来说，起点是量子力学。纳米系统存在于分子系统和宏观系统之间的过渡/界面，分子系统以量子现象为主，宏观系统的物质本质上是连续的，经典物理学提供了最好的描述。对这个介于经典和量子之间的腹地进行建模意味着融合了经典和量子力学的特征。本文提出了一种半经典方法相结合的研究方案，将经典-量子对应精确地结合到分子装置力学和动力学的描述中，并结合半经验量子力学对这些系统进行有效的结构计算。本科生和博士后研究助理将开展互补的组成部分。本科生将使用商业软件建立电子结构计算的技能，同时为分子识别和自组装建模。一名博士后研究助理将参与这些方法与纳米系统的半经典力学方法的融合。

0102848SohlbergThis proposal was received in response to NSE, NSF-0019. Nanotechnology promises engineered devices constructed from just one or a few molecules. Applications are envisioned in medicine, molecular scale electronics, and information gathering for defense, space science, and other extreme environments. Molecular turbines pumping streams of gas one molecule at a time, minuscule valves delivering drugs with unprecedented site and dose specificity, pinhead scale computer disks storing libraries of information, and extremely sensitive artificial olfaction for contraband detection, are all theoretically possible, but first these devices must be designed. The ultimate goal of the program is to develop design engineering tools - "recipes" for nano-devices by design, while simultaneously training tomorrow's engineers and scientists in their development and application. In the case of macroscopic machines, the starting point for the development of engineering models is well known: the Newtonian laws of mechanics and the Maxwellian laws of electricity and magnetism. For molecular systems the starting point is quantum mechanics. Nano-systems exist at the transition/interface between molecular systems, which are dominated by quantum phenomena, and macroscopic systems where matter is essentially continuous and classical physics provides the best description. Modeling this hinterland between the classical and the quantum means incorporating features of both classical and quantum mechanics. Here a program of study is proposed combining semiclassical methods to accurately incorporate classical-quantum correspondence into the description of molecular device mechanics and dynamics, with semiempirical quantum mechanics for efficient structure calculations on these systems. Undergraduate and postdoctoral research assistants will carry out complementary components. Undergraduates will build skills with commercial software for electronic structure calculations while modeling molecular recognition and self-assembly. A postdoctoral research assistant will be involved in the fusion of these methods with the methods of semiclassical mechanics for nano-systems.