文摘
The crystal, electronic and phonon structures, and thermodynamic stability of a hypothetical complex hydride Y2CrH6 were investigated using first-principles calculations. We found that the hydride contains CrH6 octahedra in the K2PtCl6-type structure. The electronic structure illustrates that two yttrium atoms donate a total of six electrons to the octahedra, indicating the charge state which abides by the 18-electron rule. The phonon dispersion curves demonstrate that the hydride is dynamically stable. The calculated enthalpy change of ?11 kJ/mol for the reaction, 2YH2+Cr + H2 ¡ú Y2CrH6, gives a possible route to synthesize the stable complex hydride containing [CrH6]6?. The large charge state of the hexavalent complex anion [CrH6]6? would be useful to explore new complex hydrides, providing the chemical flexibility through the multiple combinations of cations.
