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采用周期性密度泛函理论研究氧原子在δ-Pu(111)表面的吸附行为,方法为广义梯度近似(GGA),考虑了自旋极化和自旋限制不同情况。结果表明O在δ-Pu(111)面的吸附属于较强的化学作用,吸附稳定性为心式1≈心式2>桥式>顶位。2种心式位的吸附能和平衡结构几乎没有差别,化学吸附能为-6.153 eV(自旋极化)和-7.454 eV(自旋限制),O都距离表面0.131 nm。与O配位的Pu原子数目是决定化学吸附过程的主要因素,配位的数目越多,化学成键越稳定。Mulliken电荷布局分析表明,Pu和O的作用主要发生在第1层,另外2层没有影响。O原子的吸附使钚金属表面功涵增加。O的吸附为较强的离子键作用,电子相互作用主要为O_2p与Pu5f、Pu7s、Pu6d杂化轨道相互作用。
Periodic density functional theory is used to study the adsorption behavior of oxygen atoms on the δ-Pu (111) surface. The method is generalized gradient approximation (GGA), taking into account different situations of spin polarization and spin confinement. The results show that the adsorption of O on the δ-Pu (111) surface belongs to the stronger chemical reaction, and the adsorption stability is that of the core 1 ≈center 2> bridge> top. There is almost no difference between the adsorption energy and the equilibrium structure of the two kinds of heart-type sites. The chemisorption energy is -6.153 eV (spin polarization) and -7.454 eV (spin limitation), and O is 0.131 nm from the surface. The number of Pu atoms that coordinate to O is the main factor that determines the chemisorption process. The more the coordination number, the more stable the chemical bonding. Mulliken charge layout analysis shows that the role of Pu and O occurs mainly in the first layer, the other two layers have no effect. The adsorption of O atoms increases the plutonium metal surface. The adsorption of O is a strong ionic bond, and the interaction between O 2 P and Pu5f, Pu7s, Pu6d hybrid orbital is mainly due to the electronic interaction.