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在巨正则系综的密度泛函理论基础上，把Ｐａｒ等人提出的原子与分子体系的电负性与硬度的定义应用到分子片化学中，并应用密度泛函理论最新发展的ＤＦＴ－ＬＤＡ／ＮＬ方法计算了一些过渡金属羰基分子片的Ｅ（Ｎ）—ΔＮ能量曲线。结果表明，分子片的能量函数Ｅ（Ｎ）是凸函数。但是，在一般情况下，在整数电荷处出现导数不连续。因此有限差分近似被应用于分子片的电负性与硬度的具体计算。通过对典型化合物的计算表明，有限差分法的计算结果是合理的，与Ｐｅａｒｓｏｎ的实验值接近。应用ＤＦＴ－ＬＤＡ／ＮＬ计算的电负性与硬度，解释了ＨＭｎ（ＣＯ）５，［ＨＦｅ（ＣＯ）５］＋，Ｈ２Ｆｅ（ＣＯ）４和ＨＣｏ（ＣＯ）４的相对酸性；分析了［Ｍｎ（ＣＯ）５］－与Ｃｒ（ＣＯ）５，Ｃｏ（ＣＯ）－４与Ｆｅ（ＣＯ）５之间的分子片取代反应的可能路径。研究表明可以应用密度泛函理论定义的电负性与硬度，从理论上来表征分子片的化学性质。
Based on the theory of giant canonical ensemble, the definition of electronegativity and hardness of atom and molecular system proposed by Par et al. Is applied to molecular chip chemistry, and the latest development of DFT-LDA / NL method to calculate some of the transition metal carbonyl molecules E (N) -ΔN energy curve. The results show that the energy function E (N) is a convex function. However, in general, there is a discontinuity in the derivative at the integer charge. Therefore, finite difference approximation is applied to the specific calculation of the electronegativity and hardness of molecular films. The calculation of typical compounds shows that the finite difference method is reasonable, which is close to Pearson ’s experimental value. The relative acidity of HMn (CO) 5, [HFe (CO) 5] +, H2Fe (CO) 4 and HCo (CO) 4 was calculated using the DFT-LDA / NL calculations of the electronegativity and hardness. (CO) 5] - a possible pathway for molecular fragment substitution reaction with Cr (CO) 5, Co (CO) -4 and Fe (CO) 5. Studies have shown that the electronegativity and hardness defined by density functional theory can be applied to theoretically characterize the chemical properties of molecular films.