While homonuclear free trihalide anions and their alkali ion pairs have been thoroughly described experimentally and theoretically, the coverage of their heteronuclear relatives in the literature remains fragmentary. This might be merely a consequence of the large variety of possible compositions of trihalide anions, however the experimental difficulties associated with the preparation of heteronuclear trihalide anions especially those containing the lightest halogen atom F could also play a role. This paper is a systematic approach to a complete theoretical description of the free inter trihalide anions XXX⁻, XXY⁻, YXY⁻, and XYZ⁻ (X, Y, Z = F–I) and their alkali ion pairs MXXX, MYXX, MXXY, MYXY, and MXYZ (M = Li–Cs; X, Y, Z = F–Br). The minimum structures obtained from calculations at CCSD(T)/triple-ζ level of theory were analyzed and ordered with respect to trends in their structural appearance, dissociation energies, and vibrational properties. Predictions about the existence of mixed alkali trihalide anions and new insights about existing experimental data could be derived from calculated data.

虽然同核游离三卤化物阴离子及其碱金属离子对已在实验和理论上进行了全面描述，但其杂核近亲在文献中的报道仍然是零碎的。这可能仅仅是三卤化物阴离子组成可能种类繁多的结果，但是与制备异核三卤化物阴离子有关的实验困难，尤其是那些含有最轻卤素原子F的阴离子，也可能起着作用。本文是一个系统化的方法来免费的三卤间阴离子XXX的完整理论描述^-，XXY ^-，YXY ^-和XYZ ^-（X，Y，Z = F–I）及其碱离子对MXXX，MYXX，MXXY，MYXY和MXYZ（M = Li–Cs； X，Y，Z = F–Br）。分析了在CCSD（T）/triple-ζ理论水平上从计算中获得的最小结构，并就其结构外观，离解能和振动特性的趋势进行了排序。可以从计算得出的数据中得出关于混合碱式三卤化物阴离子存在的预测，以及对现有实验数据的新见解。