By interpolating a 4fq6s → 4fq7s transition within the sequence f1 → f14 rather than between f0 and f14, revised third and fourth ionization energies of the lanthanides have been obtained. The revised values, together with the second ionization energies calculated in a previous paper, are used to calculate values of the standard enthalpies of formation of the gaseous tripositive ions, ΔfHƟ(M3+,g), and of the lattice and hydration enthalpies of some lanthanide compounds and ions in the trivalent and tetravalent states. The displacements of f0 values from nearly smooth f1 → f14 variations exceed 30 kJ mol−1 and indicate substantial subshell breaks.

中文翻译：

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镧系元素电离能和亚壳断裂。第 2 部分。 第三和第四电离能

通过在序列 f1 → f14 内而不是在 f0 和 f14 之间插入 4fq6s → 4fq7s 跃迁，已经获得了修正的镧系元素的第三和第四电离能。修正后的值与之前论文中计算的第二电离能一起用于计算气态三正离子的标准形成焓 ΔfHƟ(M3+,g) 以及某些镧系元素的晶格和水合焓的值三价和四价状态的化合物和离子。几乎平滑的 f1 → f14 变化的 f0 值的位移超过 30 kJ mol-1，表明子壳发生实质性断裂。