CAREER: Towards an accurate and illuminating theory of weak interactions between open-shell systems

奥本大学的Konrad Patkowski在化学系化学理论、模型和计算方法程序的支持下，开发了一种计算开壳系统之间非共价相互作用能的新方法--对称适应微扰理论(SAPT)的多参考版本。SAPT的独特之处在于它结合了高精度和解释能力，相互作用能是对应于静电、交换排斥、感应和色散的明确定义的贡献的总和。Patkowski教授和他的团队将SAPT的适用性扩展到具有显著静态相关性的相互作用系统，这些系统不能用单一的斯莱特行列式来描述。新制定的方法被用来计算和解释涉及大气自由基、有机多自由基和金属有机骨架中吸附的小分子的相互作用能。NSF EPSCoR办公室也支持这项研究。分子之间相互作用能量的知识对于我们理解分子液体和晶体、大气反应、星际分子以及蛋白质的结构和功能至关重要。在金属有机骨架的多孔环境中，类似的相互作用将二氧化碳等小分子结合在一起。帕特科夫斯基教授和他的团队开发了一种新的方法来计算相互作用能量，这种方法可以阐明相互作用的基本物理原理。通过这种方式获得的理解有助于设计新的框架，这些框架可以在气体分离方面更加有效，特别是在消除烟道和废气中的二氧化碳方面，使其不会释放到大气中。新方法是在开放源码的计算机代码中实现的，其他研究人员可以免费获得。此外，帕特科夫斯基教授和他的团队正在奥本大学暑期科学学院的框架内开发动手计算化学模块，为有天赋的高中生提供现实的研究体验，并增强他们对科学职业的认识。

Konrad Patkowski of Auburn University is supported by the Chemical Theory, Models, and Computational Methods program in the Chemistry division to develop a new approach to computing noncovalent interaction energies between open-shell systems - a multireference version of symmetry-adapted perturbation theory (SAPT). The unique feature of SAPT is its combination of high accuracy and interpretive power, the interaction energy is obtained as a sum of well-defined contributions corresponding to electrostatics, exchange repulsion, induction, and dispersion. Prof. Patkowski and his group extend the applicability of SAPT to interacting systems with significant static correlation that cannot be described by a single Slater determinant. The newly formulated methods are used to compute and interpret interaction energies involving atmospheric radicals, organic polyradicals, and small molecules adsorbed within metal organic frameworks. The NSF EPSCoR office is also supporting this research.The knowledge of interaction energies between molecules is critical for our understanding of molecular liquids and crystals, atmospheric reactions, interstellar molecules, and the structure and function of proteins. Similar interactions bind small molecules such as carbon dioxide in the porous environment of metal organic frameworks. Prof. Patkowski and his group develop new methods to compute interaction energies in a way that elucidates the underlying physics of the interaction. The understanding gained in this way helps design new frameworks that can be more effective in gas separation, in particular, in removing carbon dioxide from flue and exhaust gases so that it does not get released into the atmosphere. The new methods are implemented in an open-source computer code that is freely available to other researchers. In addition, Prof. Patkowski and his group are developing hands-on computational chemistry modules within the framework of the Auburn University Summer Science Institute, providing realistic research experience to gifted high-school students and enhancing their awareness of the careers in science.