金属锡表面吸附氢同位素的量子力学计算

Adsorption study of hydrogen isotopes on metal tin surface by quantum mechanism computation

根据原子分子反应静力学与群论,确定了H2、D2和T2的基电子状态为1∑+g(D∞v),SnH、SnD和SnT的基电子状态为2∑+(C∞v)。应用基函数SDD 和6 311G ,密度泛函B3P86方法,计算了氢同位素分子及其锡化物的结构、能量E、定容热容Cv和熵S。H2(D2,T2),SnH(D,T)和SnH2(D2,T2)的基电子状态分别为1∑+g(D∞h),2∑+(C∞v)和3B1(C2v)。H2、D2和T2的离解能为4.5918eV,SnH(D,T)分子的离解能为2.7147eV,SnH2(D2,T2)分子的离解能为4.8339eV。用总能量中的电子和振动能量近似代表SnHn、SnDn和SnTn(n=1,2)分子处于固态时的能量,用总熵中的电子和振动熵近似代表SnH、SnD和SnT分子处于固态时的熵,从而计算了锡与H2、D2和T2反应过程的△Hf°,△Sf°,△Gf°和平衡压力,并导出他们与温度的函数关系。

Based on Atomic and Molecular Reaction Statics and Group theory, the basis sets SDD^(**) for Tin and 6-311g^(**) for H_2, and density functional (B3P86) method have been used to calculate energy E, heat capacity C_v, entropy S of hydrogen isotopes and their Tin compounds. the ground states of H_2(D_2 ,T_2),SnH(D,T), and SnH_2(D_2,T_2) are ()~1∑^+_g(D_(∞h)), ()~2∑^+(C_(∞v)), and ()~3B_1(C_(2v)),respectively.The dissociation energy of H_2(D_2,T_2), SnH(D,T) and SnH_2(D_2,T_2) are 4.591 8 eV, (2.714 7 eV) and 4.833 9 eV,respectively.The electronic and vibrational energy or entropy of the total energy or entropy are approximately used to represent the energy or entropy at solid state of SnH_n, SnD_n, SnT_n(n=1,2), then, the △H_f°,△S_f°,△G_f ° and equilibrium pressure of H_2,D_2 and T_2 with their Tin compounds can be calculated, and the relationships with temperature have also been derived by the least square fitting.