College of Geoscience and Surveying Engineering, China University of Mining and Technology, Beijing, 10083, People's Republic of China.
J Phys Chem A. 2011 Jul 28;115(29):8302-9. doi: 10.1021/jp203585p. Epub 2011 Jul 6.
The structures and energies of As(n) (n = 2-8) neutrals, anions, and cations have been systematically investigated by means of the G3 schemes. The electron affinities, ionization potentials, binding energies, and several dissociation energies have been calculated and compared with limited experimental values. The results revealed that the potential surfaces of neutral As(n) clusters are very shallow, and two types of structural patterns compete with each other for the ground-state structure of As(n) with n ≥ 6. One type is derived from the benzvalene form of As(6), and another is derived from the trigonal prism of As(6). The previous photoelectron spectrum (taken from J. Chem. Phys. 1998 , 109 , 10727 ) for As(3) has been reassigned in light of the G3 results. The experimental electron affinities of As(3) were measured to be 1.81 eV, not 1.45 eV. We inferred from the conclusion of G3 and density functional theory that the experimental electron affinities of 1.7 and 3.51 eV for As(5) are unreliable. The reliable electron affinities were predicted to be 0.83 eV for As(2), 1.80 eV for As(3), 0.54 eV for As(4), 3.01 eV for As(5), 2.08 eV for As(6), 2.93 eV for As(7), and 2.02 eV for As(8). The G3 ionization potentials were calculated to be 9.87 eV for As(2), 7.33 eV for As(3), 8.65 eV for As(4), 6.68 eV for As(5), 7.97 eV for As(6), 6.58 eV for As(7), and 7.65 eV for As(8). The binding energies per atom were evaluated to be 1.99 eV for As(2), 2.01 eV for As(3), 2.61 eV for As(4), 2.39 eV for As(5), 2.51 eV for As(6), 2.55 eV for As(7), and 2.67 eV for As(8). These theoretical values of As(2), As(3), and As(4) are in excellent agreement with those of experimental results. Several dissociation energies were carried out to examine relative stabilities. This characterized the even-numbered clusters as more stable than the odd-numbered species.
我们采用 G3 方案系统地研究了 As(n)（n=2-8）中性、阴离子和阳离子的结构和能量。计算并比较了电子亲和能、电离势、结合能和几种离解能与有限的实验值。结果表明，中性 As(n)团簇的势能面非常浅，对于 n≥6 的 As(n)的基态结构，两种结构模式相互竞争。一种类型源自 As(6)的苯并戊二烯形式，另一种源自 As(6)的三角棱柱体。先前的光电子能谱（取自 J. Chem. Phys. 1998, 109, 10727）已经根据 G3 结果重新分配。As(3)的实验电子亲和能被测量为 1.81 eV，而不是 1.45 eV。我们从 G3 和密度泛函理论的结论推断，As(5)的实验电子亲和能为 1.7 和 3.51 eV 是不可靠的。预测可靠的电子亲和能分别为 As(2)为 0.83 eV、As(3)为 1.80 eV、As(4)为 0.54 eV、As(5)为 3.01 eV、As(6)为 2.08 eV、As(7)为 2.93 eV 和 As(8)为 2.02 eV。G3 计算的电离能分别为 As(2)为 9.87 eV、As(3)为 7.33 eV、As(4)为 8.65 eV、As(5)为 6.68 eV、As(6)为 7.97 eV、As(7)为 6.58 eV 和 As(8)为 7.65 eV。每个原子的结合能分别评估为 As(2)为 1.99 eV、As(3)为 2.01 eV、As(4)为 2.61 eV、As(5)为 2.39 eV、As(6)为 2.51 eV、As(7)为 2.55 eV 和 As(8)为 2.67 eV。As(2)、As(3)和 As(4)的这些理论值与实验结果非常吻合。进行了几种离解能以检查相对稳定性。偶数个簇比奇数个物种更稳定。
