ZrMn2（110）表面结构及吸氢机理的第一性原理研究

采用基于密度泛函理论(DFT)的平面波赝势(PW-PP)方法，研究了ZrMn2（110）清洁表面结构和氢原子在表面的吸附。弛豫表面结构的计算结果表明表面结构的最表层为曲面，且表面结构的原子间隙变小。由1Zr2Mn原子组成的空位是氢原子吸附在ZrMn2（110）表面的最佳吸附位，吸附能为3.352 eV，氢原子吸附后离表面的距离为1.140 Å。Mulliken电荷布居分析表明吸附的氢原子与表面原子的相互作用主要是接近氢原子的第一层原子与氢原子的相互作用。过渡态计算表明被吸附的氢原子进入表面内部需克服的最大势垒为1.033 eV。

First-principles investigation on structures and hydrogen-adsorption mechanism of ZrMn2(110) surface

The clean surface structure and adsorption hydrogen atoms on ZrMn2(110) surface have been investigated using a Plane-wave pseudo-potential method based on the density function theory. The calculated result of the relaxed surface shows that the top layer atoms of ZrMn2(110) surface are arranged in an accidented plane and the space between atoms in ZrMn2(110) surface structure is decreased. The hollow site of 1Zr2Mn on the ZrMn2(110) surface is the favorable adsorption site with the adsorption energy of 3.352 eV and the optimized distance of 1.140 Å from absorpted hydrogen atom to the surface. Mulliken charge distribution analysis indicates that the interaction between H atom and surface atoms mainly take place in the first layer. The calculation of transition states indicates that the maximum potential barrier is 1.033 eV for absorpted hydrogen atom into ZrMn2(110) surface.