New Developments in Coupled Cluster Theory and Applications

有了化学系理论和计算计划的这笔赠款，斯库塞里亚教授将开发将耦合团簇微扰理论应用于分子电子结构研究的新算法。这一理论将有助于理解过渡金属二聚体、氢化物和乙炔的C-H键的化学键。将开展四个研究项目。(1)开壳耦合团簇方法中能量梯度解析能力的建立和实现。(2)实现包括所有单激发、双激发、三激发和四激发的全耦合簇法。(3)试图将三重激发的影响直接传递到单激发和双激发振幅上的耦合团簇方程的解。(4)用Hartree-Fock-Bogoliubov基准态代替传统的多参照态的耦合团簇理论。

With this grant in the Theoretical and Computational Program of the Chemistry Division, Professor Scuseria will develop new algorithms for the application of coupled-cluster perturbation theory to the study of molecular electronic structure. This theory will be instrumental in understanding chemical bonding in transition metal dimers, hydrides and the C-H bond of acetylene. Four research projects will be carried out. (1) The formulation and implementation of an analytical energy gradient capacity within the open shell coupled-cluster method. (2) The implementation of a full coupled-cluster method that includes all single, double, triple and quadruple excitations. (3) A solution of the coupled-cluster equations that attempts to transfer the effect of triple excitations directly onto the single and double excitation amplitudes. (4) A formulation of the coupled-cluster theory in terms of the Hartree-Fock-Bogoliubov reference state as an alternate to the conventional multi-reference approach.