The nephelauxetic parameters β^k = F^k (Ln³⁺)/F^k (Ln IV) have been determined, with k = 2, 4, 6, Ln³⁺ – lanthanide ion in crystal, and Ln IV – triply – charged lanthanide free ion. The Slater integrals F^k and the spin – orbit coupling constants ζ_4f for Pm IV and Ho IV have been estimated by interpolation from experimental values for other Ln IV. The matrix elements A of spin – orbit interaction have been calculated for the ground levels of both ions, ⁵I₄ and ⁵I₈ respectively. The correlation between β^k and the normalized ratios A(Ln³⁺)/A(Ln IV) in crystals has been considered a combined nephelauxetic effect of electrostatic and spin – orbit interactions. Stoichiometric or doped crystals containing Pm³⁺ or Ho³⁺ ions include simple and complex halogenides, oxides, oxohalides, phosphates, complex with organic ligand, and hydrates.

的电子云参数β ^ķ  = F ^ķ（LN ³⁺）/ F ^ķ（LN IV）已被确定，其中k = 2,4，6，LN ³⁺ -镧系元素离子在晶体和Ln IV -三重-带电镧系元素自由离子。铺瓦工积分˚F ^ķ和自旋-轨道耦合常数ζ _4F为PM IV和Ho IV已经从其他LN IV实验值估计通过内插。已经计算了两种离子（分别为⁵ I ₄和⁵ I _8）的地平面的自旋-轨道相互作用的矩阵元素A。β之间的相关性^ķ晶体中的归一化比值A（Ln ³⁺）/ A（Ln IV）被认为是静电和自旋-轨道相互作用的联合肾上腺素作用。包含Pm ³⁺或Ho ³⁺离子的化学计量或掺杂晶体包括简单和复杂的卤化物，氧化物，氧卤化物，磷酸盐，与有机配体的复杂化合物和水合物。