The ground state structural and energetic properties for rocksalt and cesium chloride phases of the cesium halides were explored using the random phase approximation (RPA) and beyond-RPA methods to benchmark the nonempirical SCAN meta-GGA and its empirical dispersion corrections. The importance of nonadditivity and higher-order multipole moments of dispersion in these systems is discussed. RPA generally predicts the equilibrium volume for these halides within 2.4% of the experimental value, while beyond-RPA methods utilizing the renormalized adiabatic LDA (rALDA) exchange-correlation kernel are typically within 1.8%. The zero-point vibrational energy is small and shows that the stability of these halides is purely due to electronic correlation effects. The rAPBE kernel as a correction to RPA overestimates the equilibrium volume and could not predict the correct phase ordering in the case of cesium chloride, while the rALDA kernel consistently predicted results in agreement with the experiment for all of the halides. However, due to its reasonable accuracy with lower computational cost, SCAN+rVV10 proved to be a good alternative to the RPA-like methods for describing the properties of these ionic solids.

中文翻译：

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岩盐或氯化铯：使用基于随机相近似的方法研究卤化铯结构的相对稳定性

使用随机相逼近（RPA）和超出RPA方法探索卤化铯的岩盐和氯化铯相的基态结构和能量性质，以对非经验的SCAN meta-GGA及其经验分散校正进行基准测试。讨论了在这些系统中非可加性和高阶色散多极矩的重要性。RPA通常预测这些卤化物的平衡体积在实验值的2.4％以内，而利用重新归一化的绝热LDA（rALDA）交换相关核的超出RPA方法通常在1.8％以内。零点振动能很小，表明这些卤化物的稳定性完全归因于电子相关效应。作为RPA的校正剂，rAPBE内核高估了平衡体积，在氯化铯的情况下无法预测正确的相序，而rALDA内核始终预测与所有卤化物的实验结果一致的结果。但是，由于SCAN + rVV10具有合理的准确度和较低的计算成本，因此被证明是用于描述这些离子固体性质的类似RPA的方法的良好替代品。