We report on a multiscale approach for the simulation of electrical characteristics of metal disilicide based Schottky-barrier metal oxide semiconductor field-effect transistors (SB-MOSFETs). Atomistic tight-binding method and non-equilibrium Greens function formalism are combined to calculate the propagation of charge carriers in the metal and the charge distribution at the MSi2(111)/Si(111) and MSi2(111)/Si(100) (with M=Ni, Co, and Fe) contacts. Quantum transmission coefficients at the interfaces are then computed accounting for energy and momentum conservation, and are further used as input parameters for a compact model of SB-MOSFET current-voltage simulations. In the quest for nanodevice performance optimization, this approach allows unveiling the role fo different materials in configurations relevant for heterostructure nanowires.Financed by CICYT MAT-2005-3866, MEC TEC-2006-13731-C02-01/MIC and EU (contract num. 015783 NODE)Peer reviewed