Synthesis, crystal structure and alkaline pathways simulation of K3Na(Mo0.67Cr0.33O4)2 adopting glaserite structure-type

A new compound, K 3 Na(Mo 0.67 Cr 0.33 O 4 ) 2 , had been synthesized using the flux method and characterized by single-crystal X-ray diffraction. The title compound could be considered as a new member of the Glaserite family. The crystal structure is built on (Mo/Cr)O 4 tetrahedra sharing corners with NaO 6 octahedra making a 2D formwork. The Mo 6+ and Cr 6+ cations are located at the same general site with occupancies of 0.67 and 0.37, respectively. The proposed structural model was supported by the bond valence sum and the charge distribution validation methods with suitable agreement factors. The experimental morphology of the single crystal determined by SEM technique and the simulated morphology from the crystallographic data have been reported. The simulation of the alkaline elements pathways migration by using the bond valence site energy model shows that the potassium atoms are blocked and only the sodium atoms can move. The estimated activation energy is about 1.45 eV. The crystal structure and the isosurfaces of migration of alkaline cations in crystal structure of the title compound and in the A I M III (MoO 4 ) 2 (A I = alkaline; M III = Fe 3+ , Cr 3+ , V 3+ , Al 3+ ) compounds were compared.