Cho Jun-Hyung, Kleinman Leonard
Department of Physics, Hanyang University, 17 Haengdang-Dong, Seongdong-Ku, Seoul 133-791, Korea.
J Chem Phys. 2004 Jul 15;121(3):1557-61. doi: 10.1063/1.1763835.
Two recent experiments for adsorbed acrylonitrile on the Si(001) surface reported different adsorption structures at 110 and 300 K. We investigate the reaction of acrylonitrile on Si(001) by first-principles density-functional calculations. We find that the so-called [4+2] structure in which acrylonitrile resides between two dimer rows is not only thermodynamically favored over other structural models but also easily formed via a precursor where the N atom of acrylonitrile is attached to the down atom of the Si dimer. The additional initial-state theory calculation for the C 1s core levels of adsorbed acrylonitrile provides an interpretation for the observed low- and room-temperature adsorption configurations in terms of the precursor and [4+2] structures, respectively.
最近有两个关于丙烯腈吸附在Si(001)表面的实验，报道了在110K和300K时不同的吸附结构。我们通过第一性原理密度泛函计算研究了丙烯腈在Si(001)上的反应。我们发现，所谓的[4+2]结构（即丙烯腈位于两个二聚体行之间）不仅在热力学上比其他结构模型更有利，而且很容易通过一种前驱体形成，在该前驱体中丙烯腈的N原子与Si二聚体的向下原子相连。对吸附丙烯腈的C 1s芯能级的额外初态理论计算，分别根据前驱体和[4+2]结构，对观察到的低温和室温吸附构型提供了解释。
