Chemisorption on Metal Surfaces via Density Functional Theory Embedding of Ab Initio Finite Cluster Calculations

理论与计算化学项目正在支持一项研究工作，加州大学洛杉矶分校的E.A. Carter教授将开发一种混合电子结构技术，该技术首次利用密度泛函理论获得金属的精确电子密度分布。然后使用它（连同其相应的轨道表示）来提供一组库仑和交换算符，这些算符描述了无限金属表面和具有化学吸附区域（由几个金属原子和吸附分子组成）的大块晶体的相互作用。在密度泛函理论导出的嵌入库仑和交换场存在的情况下，利用局部多参考位相相互作用方法描述了化学吸附区。目标是开发和测试这种DFT/CI混合方法，希望它将提供从第一性原理理论研究金属表面化学吸附的最准确方法。一个涉及量子化学和固体物理技术混合的新理论将被开发出来。该理论利用了以描述金属的准确性而闻名的量子物理学和以描述金属分子化学键的准确性而闻名的量子化学。这些结合在一起有望提供最准确的方法来模拟金属表面上发生的化学反应。许多重要的工业技术都依赖于这种反应，希望新的理论将有助于进一步优化这些技术。

The Theoretical and Computational Chemistry program is supporting a research effort where a hybrid electronic structure technique will be developed by Prof. E.A. Carter of UCLA that first utilizes density functional theory to obtain an accurate electron density distribution for a metal, which then is used (along with its corresponding orbital representation) to provide a set of Coulomb and exchange operators that describe the interaction of the infinite metal surface and bulk crystal with a chemisorption region (composed of a few metal atoms and an adsorbed molecule). The chemisorption region is then described using a local multireference configuration interaction method in the presence of the embedding Coulomb and exchange field derived from density functional theory. The goal is to develop and test this hybrid DFT/CI method, with the hope that it will provide the most accurate means yet of studying chemisorption on metal surfaces from first principles theories. A new theory involving a mixture of quantum chemistry and solid state physics techniques will be developed. The theory utilizes quantum physics known for its accuracy in describing metals and quantum chemistry known for its accuracy in describing metal-molecule chemical bonds. These taken together are expected to provide the most accurate means yet of modelling chemical reactions that occur on metal surfaces. Many important industrial technologies rely on such reactions and it is hoped that the new theory will help optimize such technologies further.