(BEDT-TTF)(3)CuX2Br2, X = Cl or Br displays two magnetic transitions; one (T-P) associated with a loss of moments accounted for by two S = 1/2 ions and the second to a long range (LRO) antiferromagnetic ordering (T-N), The experimental data in the paramagnetic regions hat,e been modeled by the sum of two contributing components, the BEDT-TTF and the Cu(II), the first to a hexagonal layer of BEDT-TTF (S = 1/2) where the ions dimerize at T-P and the second to a triangular layer of Cu ions. A possible mechanism for the LRO-AF transition involving RKKY is proposed.