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文中用Gibbs自由能ΔGacid定义了HX(g)的酸性强度。研究表明 ,用MP2、QCISD和B3LYP三种量化方法计算所得的HX酸性强度与文献值对比 ,其最大的相对误差仅为 2 .4 5 %。其中 ,B3LYP方法的计算结果与文献值最为接近 ,其误差在 0 .37- 1.0 9%范围内。HF气态分子有明显的氢键作用 ,其二聚体分子酸性强度ΔGacid与单体分子的ΔGacid值相比降低了约 - 5~ - 11% ,此时氟化氢气体的酸性强度已不能单从HF单体分子的ΔGacid值来衡量 ,而应考虑HF分子的氢键作用
In this paper, Gibbs free energy ΔGacid defines the acidity of HX (g). The results show that the maximum relative error of HX acid strength calculated by MP2, QCISD and B3LYP quantification method is only 2.55%. Among them, the calculation result of B3LYP method is closest to the literature value, and its error is in the range of 0.37- 1.0 9%. HF gaseous molecules have obvious hydrogen bonding, the acid strength of the dimer ΔGacid is reduced by about -5% to 11% compared with the ΔGacid value of the monomer molecule. At this time, the acid strength of hydrogen fluoride gas can no longer be obtained from HF alone The ΔGacid value of a molecule is measured, but the hydrogen bonding of an HF molecule should be considered