CAJ | 학술논문

在密度泛函理论下,计算了清洁和吸附氧原子的Cu(100)表面的驰豫和优势吸附构型.结果表明,氧原子在金属表面采用四重穴位时,具有最大的结合能,顶位吸附时结合能最小,桥位吸附时结合能居间.这一计算结果与实验报道一致.各种密度泛函方法的比较后,发现采用mPW1PW91密度泛函和LanL2dz赝势基组,能够准确给出与实验相符的计算结果.平板模型计算的分态密度图显示,在吸附过程中出现d轨道向Fermi能级移动并越过Fermi能级,而O原子的p轨道能级远离Fermi能级,表明有电子从铜原子的d轨道转移到氧原子的2p轨道,簇模型和平板模型的布居分析显示表面氧带有约0.65～0.7 e的负电荷.研究表明,采用适当的基组和泛函方法,即使采用簇模型来模拟表面,也可以获得与实验比较吻合的计算结果.
재밀도범함이론하,계산료청길화흡부양원자적Cu(100)표면적치예화우세흡부구형.결과표명,양원자재금속표면채용사중혈위시,구유최대적결합능,정위흡부시결합능최소,교위흡부시결합능거간.저일계산결과여실험보도일치.각충밀도범함방법적비교후,발현채용mPW1PW91밀도범함화LanL2dz안세기조,능구준학급출여실험상부적계산결과.평판모형계산적분태밀도도현시,재흡부과정중출현d궤도향Fermi능급이동병월과Fermi능급,이O원자적p궤도능급원리Fermi능급,표명유전자종동원자적d궤도전이도양원자적2p궤도,족모형화평판모형적포거분석현시표면양대유약0.65～0.7 e적부전하.연구표명,채용괄당적기조화범함방법,즉사채용족모형래모의표면,야가이획득여실험비교문합적계산결과.
The interaction of atomic oxygen with the clean Cu(100) surface has been studied by means of cluster and periodic slab models density functional theory in the present paper. The Cu(4,9,4) cluster and a three-layer slab with c(2×2) structure are used to model the perfect Cu(100) surface. Three possible adsorption sites,top, bridge and hollow site, were considered in the calculations. The predicted results show that the hollow site is the prefer site for atomic oxygen adsorbed on Cu(100) surface energetically. This is in good agreement with the experiment. The calculated binding energies are respective 2.014, 3.154 and 3.942 eV for top, bridge and hollow sites at mPW1PW91/LanL2dz level for the cluster model. The geometry of Cu(100) surface has also been optimized theoretically with various density functional methods and the results show that the prediction from the B3PW91/LanL2dz and mPW1PW91/LanL2dz reproduce the experimental observation.The frontier molecular orbitals and partial density of states analysis show that the electron transfer from the d orbital of substrate to the p orbital of the surface oxygen atom.