Quantum Wave Packet Study of the H + Br2 → HBr + Br Reaction on a New Ab Initio Potential Energy Surface
Quantum Wave Packet Study of the H + Br2 → HBr + Br Reaction on a New Ab Initio Potential Energy Surface
复制标题
新的从头算势能面上 H Br2 → HBr Br 反应的量子波包研究
DOI：
10.1021/acs.jpca.1c05867
复制
发表时间：
2021
影响因子：
2.9
通讯作者：
Zhang Dong H.
中科院分区：
文献类型：
--
作者：
Shang Chenyao;Chen Jun;Xu Xin;Liu Shu;Li Liucheng;Duo Liping;Zhang Dong H.
用基本不变神经网络拟合法，在UCCSD(T)/CBS水平上，基于11个 698ab的初始能量，适当地考虑了Br2原子2P3/2轨道的自旋-轨道耦合，构造了精确的HBr2体系的全局势能面。用含时波包计算方法研究了H+Br2→Hbr+BR在新PES上的反应。基态初态总角动量J=0的总反应几率不受势垒高度(−0.351千卡/摩尔)的影响。在碰撞能量为0.5 eV时，计算了反应物Br2在自由振动状态(V0=0，J0=0，10，20，30；V0=1-5，J0=0)下的总积分截面(ICS)。结果表明，初始转动激发对ICS的影响可以忽略不计，初始振动激发在一定程度上抑制了ICS的反应性。在100-1000K温度范围内，用Boltzmann平均v0=0-5的速率常数计算了TITLE反应的热速率常数，这在一定程度上高估了实验结果。
An accurate global potential energy surface (PES) for the HBr2system has been constructed using the fundamental invariant neural network fitting method based upon 11 698ab initioenergies at the UCCSD(T)/CBS level of theory, with the spin–orbit coupling of the2P3/2orbit of the Br atom properly included. The time-dependent wave packet calculations have been performed to study the H + Br2→ HBr + Br reaction on the new PES. The total reaction probabilities for total angular momentumJ= 0 for the ground initial state show no threshold due to the submerged barrier height (−0.351 kcal/mol) of the PES. The total integral cross sections (ICS) for reactant Br2in ro-vibrational states (v0= 0,j0= 0, 10, 20, 30;v0= 1–5,j0= 0) were calculated for collision energy of up to 0.5 eV. It is found that the initial rotational excitation has a negligible effect on the ICS, and the initial vibrational excitation depresses the reactivity to some extent. The thermal rate constants for the title reaction in the temperature range of 100–1000 K were calculated from the Boltzmann averaging of thev0= 0–5 rate constants, which overestimated the experimental results to some extent.