Composite Methodologies Towards Quantitative Predictions across the Periodic Table

北德克萨斯大学的安吉拉·威尔逊得到了化学学部化学理论、模型和计算方法项目的奖励，继续开发一种新的从头算复合方法——相关一致复合方法（ccCA）——它模仿了高度相关的方法（如CCSD(T)）所达到的精度，但计算成本大大降低。ccCA方法非常稳健，不仅成功地应用于基态，而且还成功地应用于激发态和过渡态，应用于从弱相互作用到高能量物质的各种化学反应，证明对单参考和多参考波函数问题以及金属和非金属化合物都是有用的。该项目的目标是开发和应用一系列可用于整个元素周期表的复合方法，从而提供适用于广泛问题和化学系统的复合方法。能量数据通常是合理分析和设计分子种类和材料所需的最关键的信息。然而，计算化学长期面临的挑战之一是实现精确的能量学，因为分子的大小有限，可以进行常规的高精度研究。对于较重的主要金属、过渡金属和f块金属来说，挑战变得更加严峻，在这些地方，实用的、高精度的方法的发展要少得多。从头算复合策略提供了一种可靠的方法，通过三维主群来预测分子的准确能量特性。本项目通过制定预测重元素能量特性的策略，并将其应用于与环境可持续性相关的化学物种和过程，来解决这些问题。这些方法通过包含在流行的计算化学软件包中被广泛传播到更广泛的科学界。威尔逊小组为广泛的学生提供科学培训，从高中到博士。

Angela Wilson of the University of North Texas is supported by an award from the Chemical Theory, Models and Computational Method program in the Chemistry Division to continue developing a novel ab initio composite method - the correlation consistent Composite Approach (ccCA) - that mimics the accuracy achieved by highly correlated methods such as CCSD(T), but at much reduced computational cost. The ccCA methodology is extraordinarily robust, and has been successfully applied not only to ground states, but also to excited states and transition states, to diverse chemistries, from weak interactions to highly energetic species, proving useful for both single reference and multireference wavefunction-based problems and for both metal and nonmetal compounds. The project goal is to develop and apply a family of composite approaches that can be used across the entire periodic table, thereby providing composite methodologies that are applicable to broad classes of problems and chemical systems. Energetic data is often the most critical information needed for rational analysis and design of molecular species and materials. However, one of the long-standing challenges in computational chemistry is in achieving accurate energetics, due to the limited size of molecules that can be studied routinely with high accuracy. The challenges become even more substantial for heavier main group, transition metal, and f-block metal species, where the evolution of practical, high accuracy approaches is much less developed. Ab initio composite strategies have provided a reliable means to predict accurate energetic properties for molecules through the 3d main group. This project addresses these issues by developing strategies for prediction of energetic properties of heavier elements, with application to chemical species and processes of relevance to environmental sustainability. The methods are widely disseminated to the broader scientific community through inclusion in popular computational chemistry software packages. The Wilson group provides scientific training to a broad range of students, from high school to doctoral.