Density functional investigation of the adsorption of a methane monolayer on an MgO(100) surface
Density functional investigation of the adsorption of a methane monolayer on an MgO(100) surface
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DOI：
10.1103/physrevb.73.195313
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发表时间：
2006-05-01
影响因子：
3.7
通讯作者：
Larese, J. Z.
中科院分区：
文献类型：
--
作者：
Drummond, Michael L.;Sumpter, Bobby G.;Larese, J. Z.
采用基于第一性原理的密度泛函方法，采用平面波基集和周期边界条件，研究了单层甲烷在MgO（100）表面的吸附。研究了镁和氧位点的吸附，以及甲烷的取向，其中一个、两个或三个氢原子指向表面。此外，通过考虑表面平动对称并伴有甲烷分子适当旋转的排列，研究了一个甲烷分子对其相邻分子的影响。最小能量构型的甲烷分子位于表面镁原子的正上方，C-2v分子的主轴垂直于表面平面，氢原子对沿着晶格线定向，晶格线包括相邻的（表面）氧原子。此外，相邻的甲烷分子被旋转90度，以减少H-H的空间相互作用。这一安排对其他拟议的类似安排的稳定性有直接影响。
The adsorption of a monolayer of methane upon the (100) surface of MgO was studied using a first-principles-based density functional approach employing a plane-wave basis set and periodic boundary conditions. Adsorption at both magnesium and oxygen sites was investigated, as were methane orientations where one, two, or three hydrogen atoms point toward the surface plane. In addition, the effect of one methane molecule on its neighbors was investigated by considering arrangements where translational symmetry across the surface was accompanied by appropriate rotations of the methane molecule. The minimum-energy configuration has the methane molecules located directly above a surface magnesium atom, the principal axis of the C-2v molecule is normal to the surface plane, and pairs of hydrogen atoms are oriented along the lattice lines that include adjacent (surface) oxygen atoms. Furthermore, neighboring methane molecules are rotated by 90 degrees to reduce the H-H steric interactions. This arrangement has direct ramifications for the stability of other proposed, similar arrangements.