Trabelsi Tarek, Francisco Joseph S
Department of Earth and Environment Science, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6243, USA.
J Chem Phys. 2020 Feb 14;152(6):064304. doi: 10.1063/1.5134838.
We report the one-dimensional cuts of the six-dimensional potential energy surfaces (PESs) of the ground and lowest doublet and quartet electronic states of trans-HO at the MRCI-F12/aug-cc-pVTZ level of theory. Theoretical calculations predict that the first excited state (AA) presents a real minimum on its PES and possesses a nonplanar structure. The adiabatic excitation energy at the MRCI+Q and MRCI-F12 levels shows that the AA state lies in the near-infrared region. Both the transition dipole moment and the oscillator strength were predicted to be weak, which suggests that photodissociation of HO to produce OH and O after UV-Vis absorption is not a plausible mechanism. The harmonic vibrational frequencies and rotational constants of the weakly bound complex OH-O in the two electronic states were predicted to help in its detection. Our PES shows that the reactions of H + O or HO + O in their ground states do not lead to trans-HO in its ground electronic state if one of the component fragments, i.e., HO(AA') + O(P) or H(S) + O(B), is excited.
我们报告了在MRCI-F12/aug-cc-pVTZ理论水平下反式-HO的基态、最低双重态和四重态电子态的六维势能面（PESs）的一维切割。理论计算预测，第一激发态（AA）在其势能面上呈现出一个真实的极小值，并且具有非平面结构。MRCI+Q和MRCI-F12水平下的绝热激发能表明，AA态位于近红外区域。预测跃迁偶极矩和振子强度都很弱，这表明紫外-可见吸收后HO光解离产生OH和O不是一个合理的机制。预测两个电子态中弱束缚复合物OH-O的谐波振动频率和转动常数有助于其检测。我们的势能面表明，如果组成碎片之一，即HO(AA') + O(P)或H(S) + O(B)被激发，基态的H + O或HO + O反应不会产生基态电子态的反式-HO。
