应用第一性原理研究置氢α钛晶体的电子结构和性能

Electronic Structure of α-Titanium with Hydrogen Using First-Principles

基于第一性原理方法和α钛晶体计算模型,计算了α钛置氢后的能带结构、电子能态密度、价电荷密度和电荷聚居数的变化情况。结果表明:置氢不仅改变了α钛晶体能带结构的对称性,而且氢原子的离子化使能带结构发生了畸变;随着置氢量的增加,氢原子的s轨道与其临近的α钛原子的p轨道和d轨道杂化,形成钛氢共价键;氢原子周围的电荷密度发生了显著变化,形成了区域共有电子区;与氢原子越近电荷转移程度越大,则α钛原子正电性越强,并且在相同区域内α钛原子的电荷转移情况相同,使得α钛原子间相互排斥作用加强,从整体上降低了α钛原子间结合力。

The variation of band structure, density of states, charge density and atomic populations for the α-titanium with hydrogen were calculated with help of the first principle method and the calculation model of α-titanium crystal. The calculated results show that the hydrogen affects the symmetry of band structure and the aberration of band structure resulting from hydrogen ion; the covalent bond of titanium-hydrogen forms as the orbit intertexture between the s orbit of hydrogen with the p and d orbits of α-titanium with the increasing of hydrogen content; the electron zone of intercommunity forms as the great change of charge density around hydrogen; the smaller the distance from hydrogen, the more the charge transfer and the stronger the positive electricity of α-titanium, and the repulsion strengthens and the combination between α-titanium decreases at the same charge transfer of α-titanium in the same zone.