Du Shiyu, Francisco Joseph S, Schenter Gregory K, Iordanov Tzvetelin D, Garrett Bruce C, Dupuis Michel, Li Jun
Department of Chemistry, Purdue University, West Lafayette, Indiana 47907-1393, USA.
J Chem Phys. 2006 Jun 14;124(22):224318. doi: 10.1063/1.2200701.
The OH radical is one of the most important oxidants in the atmosphere due to its high reactivity. The study of hydrogen-bonded complexes of OH with the water molecules is a topic of significant current interest. In this work, we present the development of a new analytical functional form for the interaction potential between the rigid OH radical and H(2)O molecules. To do this we fit a selected functional form to a set of high level ab initio data. Since there is a low-lying excited state for the H(2)O.OH complex, the impact of the excited state on the chemical behavior of the OH radical can be very important. We perform a potential energy surface scan using the CCSD(T)/aug-cc-pVTZ level of electronic structure theory for both excited and ground states. To model the physics of the unpaired electron in the OH radical, we develop a tensor polarizability generalization of the Thole-type all-atom polarizable rigid potential for the OH radical, which effectively describes the interaction of OH with H(2)O for both ground and excited states. The stationary points of (H(2)O)(n)OH clusters were identified as a benchmark of the potential.
由于其高反应活性，羟基自由基（OH）是大气中最重要的氧化剂之一。对OH与水分子形成的氢键复合物的研究是当前一个备受关注的重要课题。在这项工作中，我们展示了一种针对刚性OH自由基与H₂O分子之间相互作用势的新分析函数形式的发展。为此，我们将一种选定的函数形式拟合到一组高水平的从头算数据上。由于H₂O·OH复合物存在一个低激发态，该激发态对OH自由基化学行为的影响可能非常重要。我们使用CCSD(T)/aug-cc-pVTZ电子结构理论水平对激发态和基态都进行了势能面扫描。为了模拟OH自由基中未成对电子的物理性质，我们对OH自由基开发了一种Thole型全原子可极化刚性势的张量极化率推广，它有效地描述了OH在基态和激发态下与H₂O的相互作用。(H₂O)ₙOH团簇的驻点被确定为该势的一个基准。
