Reliable Predictions for Thermochemical and Spectroscopic Properties by ab initio Theory:
报告题目：Reliable Predictions for Thermochemical and Spectroscopic Properties by ab initio Theory:
From Main Group Compounds to Transition Metal-Containing Triatomics
报 告 人：Kai-Chung Lau
Using the state-of-the-art ab initio method, reliable theoretical predictions on ionization energy (IE), bond dissociation energy (D0) and heats of formation (Hf) for first-row hydrides, hydrocarbon radicals, heterocyclic molecules, halogenated species and transition metal complexes are presented. The ab initio CCSDTQ/CBS approach involves the approximation to the complete basis set (CBS) limit at the coupled cluster level with single and double excitations plus quasi-perturbative triple excitations [CCSD(T)] plus higher-order corrections upto triplet and quadruple excitations (CCSDTQ). Zero-point vibrational energy correction, core-valence electronic correction, spin-orbit coupling, relativistic effect correction are included in the predictions. The ultimate level of theory of our predictions is as effective as the CCSDTQ/CBS level. The predicted IE, D0 and Hf values have been critically benchmarked with experimental data obtained from high-resolution spectroscopic measurements. This benchmarking effort allows us to conclude that (i) the nominal single-reference CCSDTQ/CBS is capable of predicting thermochemical properties with an uncertainty of ±60 meV (6 kJ/mol); (ii) the higher-order coupled cluster triple and quadruple excitations are important for electronic correlation of molecules with significant multi-reference characters and (iii) the full triple and quadruple excitations and relativistic effects are critical for accurate thermochemical predictions of transition metal triatomics.
香港城市大学化学系副教授(终身教职)，现任香港城市大学化学系副系主任。主要采用高精度从头算方法研究小分子体系的光谱与热力学性质，在JACS,Angew Chem,Chem Eur 等国际知名刊物发表多篇研究文章。