Bond Enthalpies in 975 Binary Intermetallic Compounds

This dataset reports the bond strengths between atoms in condensed intermetallic compounds. The concept of a bond energy between a pair of atoms is well-established in chemistry and physics. In materials science, it’s a fundamental parameter in thermodynamic models such as the regular, quasi-chemical and sub-regular solution models and the central atoms model. Accurate bond dissociation enthalpies are available for gaseous molecular compounds, but these values are likely to differ significantly from single bond strengths between atoms in liquids and solids. Interatomic potential functions have been developed for a range of atomic pairs by fitting to observed quantities. However, these functions often contain invariant transformations that can give bond energies that differ significantly (by up to a factor of four in some systems) from values provided by other potentials for the same system, even though both may produce the same physical properties. The present dataset gives the bond strengths between like atom pairs for nearly all elements, and for bonds between both like and unlike atom pairs in 975 intermetallic, covalent and ionic compounds drawn from 458 diferent binary systems. Typical errors in the values reported here (from enthalpy measurements) are ±4%, and larger errors of about ±10-30% occur for a small subset of values where the number of bonds in the structure are difficult to establish. Used appropriately, these bond enthalpies enable classical approximations that—to first order—can capture critical properties and phenomena. Validations have already been performed in the earlier work by estimating elemental fusion enthalpies and surface energies, as well as formation enthalpies for ternary intermetallic compounds. A wide range of other estimates are possible, including the energies of vacancies and other atomic defects, solution enthalpies for complex, concentrated solid solution alloys (CCAs), formation enthalpies of higher-order compounds, and metallic glass stability. These bond enthalpies may also be useful for establishing trends in systematic studies that cover many systems, thus narrowing the scope of subsequent experimental measurements or computations which are more accurate, but are also more difficult and time consuming.

本数据集收录了凝聚态金属间化合物的原子间键合强度数据。原子对间的键能概念在化学与物理领域已得到广泛确立。在材料科学研究中，键能是正规溶液模型、准化学模型、亚正规溶液模型以及中心原子模型等热力学模型的核心参数。气态分子化合物的键解离焓可精准测定，但此类数值与液态、固态中原子间单键键合强度往往存在显著差异。学界已通过拟合观测所得的物理量，为多组原子对构建了原子间势函数。然而这类势函数通常包含不变变换项，即便不同势函数可生成相同的物理性质，同一体系下不同势函数给出的键能仍可能存在显著差异——部分体系中差值可达四倍之多。本数据集涵盖了几乎所有元素的同原子对键合强度，同时收录了来自458个二元体系的975种金属间、共价及离子化合物的同原子对与异原子对键合强度数据。本次报道的数值典型误差（源于焓值测量）为±4%；对于部分难以确定结构中键数的少量数据，误差可达±10%~30%。若合理使用此类键焓，可借助经典近似方法（至一阶近似水平）捕捉体系的关键性质与物理现象。既往研究已通过估算元素熔化焓、表面能以及三元金属间化合物生成焓，完成了对本数据集的验证工作。该数据集还可支撑多类其他估算工作，例如空位及其他原子缺陷的能量、复杂浓缩固溶合金（Complex Concentrated Solid Solution Alloys, CCAs）的溶解焓、高阶化合物生成焓以及金属玻璃稳定性分析。此类键焓还可用于梳理多体系系统性研究中的变化趋势，从而缩小后续高精度实验测量或计算研究的范围——尽管后者精度更高，但往往耗时更久、操作难度更大。