Layered organic conductors κ-(BEDT-TTF)2X: magnetic and superconducting properties

κ-(ET)2X are described by a two bands model. We investigate the superconductivity pairing due to spin fluctuations. The superconductivity coupling constants of various pairing symmetries are calculated. They strongly depend on the nesting properties and on the species of the anion X. These nesting properties may mimic either chemical or hydrostatic pressure. The found results provide a plausible explanation for the available experiments.