Minenkov Yury, Sliznev Valery V, Cavallo Luigi
Physical Sciences and Engineering Division, King Abdullah University of Science and Technology, KAUST Catalysis Center , Thuwal 23955-6900, Saudi Arabia.
Ivanovo State University of Chemistry and Technology , Research Institute for Thermodynamics and Kinetics of Chemical Processes, 153460 Ivanovo, Russian Federation.
Inorg Chem. 2017 Feb 6;56(3):1386-1401. doi: 10.1021/acs.inorgchem.6b02441. Epub 2017 Jan 17.
Accurate gas phase formation enthalpies, ΔH, of metal oxides and halides are critical for the prediction of the stability of high temperature materials used in the aerospace and nuclear industries. Unfortunately, the experimental ΔH values of these compounds in the most used databases, such as the NIST-JANAF database, are often reported with large inaccuracy, while some other ΔH values clearly differ from the value predicted by CCSD(T) methods. To address this point, in this work we systematically predicted the ΔH values of a series of these compounds having a group 4, 6, or 14 metal. The ΔH values in question were derived within a composite Feller-Dixon-Peterson (FDP) scheme based protocol that combines the DLPNO-CCSD(T) enthalpy of ad hoc designed reactions and the experimental ΔH values of few reference complexes. In agreement with other theoretical studies, we predict the ΔH values for TiOCl, TiOF, GeF, and SnF to be significantly different from the values tabulated in NIST-JANAF and other sources, which suggests that the tabulated experimental values are inaccurate. Similarly, the predicted ΔH values for HfCl, HfBr, HfI, MoOF, MoCl, WOF, WOCl, GeO, SnO, PbBr, PbI, and PbO also clearly differ from the tabulated experimental values, again suggesting large inaccuracy in the experimental values. In the case when largely different experimental values are available, we point to the value that is in better agreement with our results. We expect the ΔH values reported in this work to be quite accurate, and thus, they might be used in thermodynamic calculations, because the effects from core correlation, relativistic effects, and basis set incompleteness were included in the DLPNO-CCSD(T) calculations. T1 and T2 values were thoroughly monitored as indicators of the quality of the reference Hartree-Fock orbitals (T1) and potential multireference character of the systems (T2).
金属氧化物和卤化物精确的气相生成焓（ΔH）对于预测航空航天和核工业中使用的高温材料的稳定性至关重要。不幸的是，在最常用的数据库（如NIST - JANAF数据库）中，这些化合物的实验ΔH值往往报道得很不准确，而其他一些ΔH值明显不同于耦合簇单双激发耦合微扰理论（CCSD(T)）方法预测的值。为了解决这一问题，在本工作中，我们系统地预测了一系列含有第4、6或14族金属的这些化合物的ΔH值。所讨论的ΔH值是在基于复合费勒 - 迪克森 - 彼得森（FDP）方案的协议中得出的，该方案结合了临时设计反应的DLPNO - CCSD(T)焓和少数参考配合物的实验ΔH值。与其他理论研究一致，我们预测TiOCl、TiOF、GeF和SnF的ΔH值与NIST - JANAF及其他来源列表中的值有显著差异，这表明列表中的实验值不准确。同样，预测的HfCl、HfBr、HfI、MoOF、MoCl、WOF、WOCl、GeO、SnO、PbBr、PbI和PbO的ΔH值也明显不同于列表中的实验值，再次表明实验值存在很大的不准确性。在有很大差异的实验值可用的情况下，我们指出与我们的结果更一致的值。我们预计本工作中报道的ΔH值相当准确，因此，它们可用于热力学计算，因为在DLPNO - CCSD(T)计算中包含了核心相关、相对论效应和基组不完备性的影响。T1和T2值作为参考哈特里 - 福克轨道质量（T1）和系统潜在多参考特征（T2）的指标进行了全面监测。
