An ab initio density functional study was performed investigating the adsorption of CO$_2$ on the neutral boron B$_{n}$ ($n = 10-13$) clusters, characterized by planar and quasiplanar ground-state atomic structures. For all four clusters, we found strong chemisorption energy of CO$_2$ reaching 1.6 eV for B$_{12}$ at the cluster edge sites with the adsorbed molecule in the plane of the cluster. A configuration with chemisorbed dissociated CO$_2$ molecule also exists for B$_{11}$ and B$_{13}$ clusters. The strong adsorption is due to the bending of the CO$_2$ molecule, which provides energetically accessible fully in-plane frontier molecular orbitals matching the edge states of the clusters. At the same time, the intrinsic dipole moment of a bent CO$_2$ molecule facilitates the transfer of excess electronic charge from the cluster edges to the molecule.
First-principles and semi-empirical van der Waals study of thymine on Cu(110) surface
本文采用密度泛函理论计算方法研究了胸腺嘧啶（C $_5$ H $_6$ N $_2$ O $_2$）分子在Cu（110）表面的吸附几何构型和成键机理.在最稳定的能量配置中，分子平面沿着$[1\bar{1}0]$方向垂直于衬底取向。对于这种吸附几何形状，胸腺嘧啶分子通过一个去质子化的氮原子和两个氧原子与表面相互作用，使得键合机制涉及最高占据分子轨道（HOMO）和基底的d-态之间的强杂交。在平行吸附几何形状的情况下，长程范德华相互作用对分子表面几何形状和吸附能都起着重要作用。通过半实证和无缝对接的方法分析了它们的具体作用。特别是，对于一个平面的配置，包括分散效果显着改变的字符的吸附过程从物理吸附到化学吸附。最后，我们通过模拟扫描隧道显微镜（STM）图像预测了分子-表面界面的真实空间形貌。从这些模拟，我们预计，只有某些吸附几何形状可以在STM实验中成像。
