摘要
用量子力学B3P86方法 ,对H、D、T采用基函数 6 311G ,对Y采用SDD ,计算了H2 、D2 、T2 及其钇化合物YHn,YDn,YTn(n =1,2 ,3)的热力学性质 ,导出H与Y反应的ΔrH m、ΔrS m、ΔrG m 和平衡压力与温度的函数关系。文献值La LaH2 的氢化反应热为 - 2 0 9 2 96kJ/mol,本文计算值Y YH2 在 2 98～ 70 0K间为 137 875到 15 5 4 77kJ/mol。LaH2 7的分解温度 (平衡压力为 0 1MPa时的平衡温度 )文献值为 112 4℃ ,本文计算YH2 的分解温度为 782 9K。
Based on atomic and molecular reaction statics and group theory, the ground states ()~1Σ^+(C_(∞v)) of YH,YD and YT,()~2A_1(C_(2V)) of YH_2,YD_2 and YT_2 and ()~1A′_1 (D_(3H)) of YH_3,YD_3 and YT_3 are derived. The basis sets SDD^(**) for Y and 6-311g^(**) for H_2,and density functional (B3P83) method are used to calculate energy E, heat capacity Cv, entropy S of hydrogen isotopes and their Yttrium compounds. 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 YH_n,YD_n,YT_n (n=1,2,3), then, the Δ_fH^( )_m,Δ_fS^( )_m,Δ_fG^( )_m and equilibrium pressure of H_2,D_2 and T_2 with their Yttrium compounds can be calculated, and the relationships with temperature could also be derived by the least square fitting.
出处
《化学研究与应用》
CAS
CSCD
北大核心
2004年第4期489-492,共4页
Chemical Research and Application
