Pressure and temperature dependence of the structural properties of the molecular semi - conducting salt /spl alpha/-ET/sub 2/Ag(CN)/sub 2/

Summary form only given. The molecular charge transfer salt /spl alpha/-ET/sub 2/Ag(CN)/sub 2/ undergoes a structural phase transition, between two semi-conducting phases, whose critical temperature, near to 300K, depends on pressure. This transition is cristallographically characterised by the appearance of 1/2 b* superlattice reflections at high pressure or low temperature. The isobaric thermal expansions and the isothermal compressibilities are calculated from the values of the lattice parameters (330 to 85K at ambient pressure; ibar to 12.4 kbar at room temperature). The electronic properties are deduced from, the ambient pressure (295 and 120K) and room temperature (5.4, 8 and 1 1kbar) crystal structures.