物理化学学报 >> 2009, Vol. 25 >> Issue (11): 2305-2311.doi: 10.3866/PKU.WHXB20091019

研究论文 上一篇    下一篇

Ni(110)-p2mg(2×1)-CO表面的几何结构和电子态

赵新新, 陶向明, 宓一鸣, 陈戍, 谭明秋   

  1. 上海工程技术大学基础教学学院, 上海 201620|浙江大学物理系, 杭州 310027
  • 收稿日期:2009-04-22 修回日期:2009-07-01 发布日期:2009-10-28
  • 通讯作者: 赵新新 E-mail:bighunter@suse.edu.cn

Geometric Structures and Electronic States of Ni(110)-p2mg(2×1)-CO Surface

ZHAO Xin-Xin, TAO Xiang-Ming, MI Yi-Ming, CHEN Shu, TAN Ming-Qiu   

  1. School of Fundamental Studies, Shanghai University of Engineering Science, Shanghai 201620, P. R. China|Department of Physics, Zhejiang University, Hangzhou 310027, P. R. China
  • Received:2009-04-22 Revised:2009-07-01 Published:2009-10-28
  • Contact: ZHAO Xin-Xin E-mail:bighunter@suse.edu.cn

摘要:

利用密度泛函理论(DFT)总能计算研究了Ni(110)-p2mg(2×1)-CO表面的原子结构和电子态. 计算结果表明: CO分子吸附于该表面的短桥位附近, 分子吸附能为1.753 eV, CO分子的键长dC—O为0.117 nm, 分子与表面竖直方向的夹角为20.0°, 碳原子和短桥位中点的连线与竖直方向的夹角为20.9°; 吸附的CO分子内原子间的伸缩振动频率为1876和1803 cm-1. 态密度研究结果表明吸附作用主要来自CO分子π、σ轨道与衬底d轨道间的杂化作用. CO分子σ轨道和衬底表面镍原子dxz轨道杂化形成的表面电子态主要位于费米能以下-10.4 至-8.8 eV和-7.4至-5.1 eV 范围内. σ和dxz轨道间的杂化作用可能是形成p2mg表面对称性的重要因素之一.

关键词: 密度泛函理论, Ni(110)-p2mg(2×1)-CO, 吸附能, 分子振动, 态密度

Abstract:

First-principles calculations were performed to determine the geometric structure and electronic states of Ni(110)-p2mg(2×1)-CO surface. We found that the CO molecules were adsorbed onto nearby short bridge sites. The molecular adsorption energy was calculated to be 1.753 eV. The C—O bond length was about 0.117 nm. The angle between the bond of the CO molecule and the vertical of the Ni(110) surface was 20.0°. The tilt angle of the direction linking the carbon and the center of the short bridge was 20.9°. The stretch vibration frequencies between the carbon and the oxide atoms of an adsorbed CO molecule was 1876 and 1803 cm-1. The density of states suggests that the chemical interaction between the CO molecules and Ni atoms was mainly caused by hybridization between molecular orbitals π, σ and d orbitals. Surface p2mg(2×1) reconstructionmay be attributed to the hybridization between σ molecular orbitals of CO and dxz orbitals of nickel atoms. Surface electronic states resulting from an interaction between σ molecular orbitals of CO and dxz orbitals of nickel atoms were localized below the Fermi energy (0 eV) from -10.4 to -8.8 eV and from -7.4 to -5.1 eV.

Key words: Density functional theory, Ni(110)-p2mg(2×1)-CO, Adsorption energy, Molecule vibration, Density of states

MSC2000: 

  • O641