Wu Ping, Liu Qingxiu, Chen Gang
Department of Physics, University of Jinan Shandong 250022 China
RSC Adv. 2019 Jul 5;9(36):20989-20999. doi: 10.1039/c9ra02202c. eCollection 2019 Jul 1.
Conventional density functional theory calculations heavily bias planar structures in gold clusters, failing to predict the structural transition from planar to three-dimensional geometries in experimentally detected gold species. Inspired by recent progress in calculating the defect energies of coinage metals with nonlocal effect-enhanced hybrid functionals, we have studied nonlocal effects in gold clusters. Although the hybrid functional was accurate for bulk gold, it heavily biased the planar structure for gold clusters. By including dispersive interactions into semilocal density functional calculations, we obtained an accurate vacancy formation energy of 0.72 eV for bulk gold along with the correct structural transition for gold clusters. The transition was found to occur at Au for gold anions and at Au for gold cations, agreeing very well with the experimental results. For neutral gold clusters, we found the transition to occur at Au, indicating the need for experimental verification. The results show the importance of nonlocal effects in the study of gold clusters, calling for further comprehensive theoretical and experimental studies to evaluate nonlocal effects in Au and other precious metals.
传统的密度泛函理论计算严重偏向金团簇中的平面结构，无法预测实验检测到的金物种中从平面几何结构到三维几何结构的结构转变。受近期利用非局部效应增强的杂化泛函计算货币金属缺陷能量的进展启发，我们研究了金团簇中的非局部效应。尽管杂化泛函对体相金是准确的，但它严重偏向金团簇的平面结构。通过将色散相互作用纳入半局部密度泛函计算，我们得到了体相金准确的空位形成能为0.72 eV，同时也得到了金团簇正确的结构转变。发现该转变对于金阴离子发生在Au ，对于金阳离子发生在Au ，与实验结果非常吻合。对于中性金团簇，我们发现转变发生在Au ，这表明需要进行实验验证。结果表明非局部效应在金团簇研究中的重要性，需要进一步进行全面的理论和实验研究来评估Au和其他贵金属中的非局部效应。
