Eleven examples of hexagonal and orthorhombic polymorphs of intermetallic compounds having 5:3 stoichiometry are listed in the International Crystal Structure Database. A transition temperature between them has only been determined for the Yb–Sb and Sr–Bi systems, but results on the Sr–Bi system are discrepant with those on the Yb–Sb system, in which the phase relationships are well constrained by experimental data, for example, that the lower-temperature polymorph is the prototype orthorhombic Yb₅Sb₃ structure (αY₅Sb₃) and the higher temperature polymorph (βYb₅Sb₃) is isostructural with hexagonal Mn₅Si₃, with the transformation occurring at 1280 °C. In contrast, thermodynamic modeling on the Sr–Bi system give the inverse sequence of polymorphs with increasing temperature. It appears unlikely that the hexagonal Mn₅Si₃ structure type can be stable at higher temperatures than the orthorhombic Yb₅Sb₃ structure in one system, while orthorhombic Yb₅Sb₃ structure is the stable phase at higher temperatures in another system. The discrepancy can be attributed to the limited experimental data used to model the phase relationships in the Sr–Bi system.

国际晶体结构数据库中列出了 11 个具有 5:3 化学计量比的金属间化合物的六方和斜方多晶型物的例子。它们之间的转变温度仅针对 Yb-Sb 和 Sr-Bi 系统确定，但 Sr-Bi 系统的结果与 Yb-Sb 系统的结果不一致，其中相关系受到实验数据的良好约束例如，低温多晶型物是原型斜方晶 Yb ₅ Sb ₃结构（αY ₅ Sb ₃），高温多晶型物（βYb ₅ Sb ₃）与六方 Mn ₅ Si ₃同构，转变发生在 1280 °C。相比之下，Sr-Bi 系统的热力学模型给出了随温度升高的多晶型物的逆序。六方Mn ₅ Si ₃结构类型在一个系统中似乎不太可能比正交Yb ₅ Sb ₃结构在更高的温度下稳定，而正交Yb ₅ Sb ₃结构在另一个系统中在较高温度下是稳定相。这种差异可归因于用于模拟 Sr-Bi 系统中的相关系的有限实验数据。