Electron Transfer and the Valence States of Cerium and Platinum in Cubic Friauf-Laves Compounds with the Platinum Metals

An analysis of the observed values of the lattice constants of the crystalline solutions Ce${\mathrm{Ir}}_2$-Ce${\mathrm{Pt}}_2$ and other Friauf-Laves intermetallic compounds leads to the conclusion that at 14 at.% Ce${\mathrm{Pt}}_2$ in Ce${\mathrm{Ir}}_2$ the platinum atom has transferred one electron to cerium and forms nine covalent bonds in pivoting resonance, without having a metallic orbital, whereas in La${\mathrm{Pt}}_2$ and Ce${\mathrm{Pt}}_2$ it has 0.72 metallic orbital, an unshared electron pair, and covalence 7.28. The choice of valence states $3^{+}$ and $4^{+}$ of cerium in different compounds is also discussed.