Chemistry Department, Shelby Hall, The University of Alabama, Box 870336, Tuscaloosa, Alabama 35487-0336, USA.
J Phys Chem A. 2010 Apr 1;114(12):4272-81. doi: 10.1021/jp911735c.
Geometry parameters, frequencies, heats of formation, and bond dissociation energies are predicted for simple alkali metal compounds (hydrides, chlorides, fluorides, hydroxides and oxides) of Li, Na, and K from coupled cluster theory [CCSD(T)] calculations including core-valence correlation with the aug-cc-pwCVnZ basis set (n = D, T, Q, and 5). To accurately calculate the heats of formation, the following additional correction were included: scalar relativistic effects, atomic spin-orbit effects, and vibrational zero-point energies. For calibration purposes, the properties of some of the lithium compounds were predicted with iterative triple and quadruple excitations via CCSDT and CCSDTQ. The calculated geometry parameters, frequencies, heats of formation, and bond dissociation energies were compared with all available experimental measurements and are in excellent agreement with high-quality experimental data. High-level calculations are required to correctly predict that K(2)O is linear and that the ground state of KO is (2)Sigma(+), not (2)Pi, as in LiO and NaO. This reliable and consistent set of calculated thermodynamic data is appropriate for use in combustion and atmospheric simulations.
从耦合簇理论 [CCSD(T)] 计算中预测了 Li、Na 和 K 的简单碱金属化合物（氢化物、氯化物、氟化物、氢氧化物和氧化物）的几何参数、频率、生成热和键离解能，包括与 aug-cc-pwCVnZ 基组（n = D、T、Q 和 5）的核价相关。为了准确计算生成热，还包括了以下附加修正：标量相对论效应、原子自旋轨道效应和振动零点能。为了校准目的，通过 CCSDT 和 CCSDTQ 对一些锂化合物的性质进行了迭代三激发和四激发预测。计算的几何参数、频率、生成热和键离解能与所有可用的实验测量值进行了比较，并与高质量的实验数据非常吻合。需要进行高精度的计算才能正确预测 K(2)O 是线性的，并且 KO 的基态是 (2)Sigma(+)，而不是 LiO 和 NaO 中的 (2)Pi。这套可靠且一致的计算热力学数据适用于燃烧和大气模拟。
