Composite Methodologies Towards Quantitative Predictions across the Periodic Table

北得克萨斯大学的Angela Wilson得到了化学部化学理论、模型和计算方法项目的支持，继续开发一种新的从头合成方法-关联一致合成方法(CCCA)-该方法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方法是非常稳健的，它不仅成功地应用于基态，而且已经成功地应用于激发态和过渡态，从弱相互作用到高能物种的各种化学，证明了对基于单参考和多参考波函数的问题以及对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类别的问题和化学系统的复合方法。高能数据往往是合理分析和设计分子物种和材料所需的最关键的信息。然而，计算化学中长期存在的挑战之一是实现精确的能量学，因为可以高精度进行常规研究的分子的尺寸有限。对于较重的主族、过渡金属和f-块金属物种来说，挑战变得更加严峻，在这些物种中，实用的高精度方法的发展要落后得多。从头算合成策略为通过3D主基准确预测分子的能量性质提供了可靠的手段。该项目通过制定预测较重元素的能量性质的战略来解决这些问题，并将其应用于与环境可持续性相关的化学物种和过程。通过包含在流行的计算化学软件包中，这些方法被广泛传播给更广泛的科学界。威尔逊团队为范围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.