Thermal, dielectric and vibrational properties of ferroelastic [(CH3)3PH]3[Sb2Cl9] crystal. Molecular motion of trimethylphosphonium cations studied by proton magnetic resonance

The schematic diagram of crystal structure of [(CH3)3PH]3[Sb2Cl9] showing two types of trimethylphosphonium cations and their proton spin-lattice relaxation time as a function of 1000/T.