Zhang Hui, Zhang Gui-Ling, Liu Jing-Yan, Sun Miao, Liu Bo, Li Ze-Sheng
College of Chemical and Environmental Engineering, Harbin University of Science and Technology, Harbin 150080, People's Republic of China.
J Comput Chem. 2009 Jan 30;30(2):236-42. doi: 10.1002/jcc.21047.
The multiple-channel reactions SiH(3) + SiH(CH(3))(3) --> products are investigated by direct dynamics method. The minimum energy path (MEP) is calculated at the MP2/6-31+G(d,p) level, and energetic information is further refined by the MC-QCISD (single-point) method. The rate constants for individual reaction channels are calculated by the improved canonical variational transition state theory with small-curvature tunneling correction over the temperature range of 200-2400 K. The theoretical three-parameter expression k(T) = 2.44 x 10(-23)T(3.94) exp(-4309.55/T) cm(3)/(molecule s) is given. Our calculations indicate that hydrogen abstraction channel R1 from SiH group is the major channel because of the smaller barrier height among five channels considered.
采用直接动力学方法研究了多通道反应SiH(3) + SiH(CH(3))(3) → 产物。在MP2/6 - 31+G(d,p)水平上计算了最小能量路径（MEP），并通过MC - QCISD（单点）方法进一步完善了能量信息。在200 - 2400 K的温度范围内，采用改进的正则变分过渡态理论并结合小曲率隧道效应校正，计算了各个反应通道的速率常数。给出了理论三参数表达式k(T) = 2.44 x 10(-23)T(3.94) exp(-4309.55/T) cm(3)/(分子·秒)。我们的计算表明，在所考虑的五个通道中，由于SiH基团的氢提取通道R1的势垒高度较小，所以它是主要通道。
