  In the aim of determining accurate iron abundances in stars, this work is
meant to empirically calibrate H-collision cross-sections with iron, where no
quantum mechanical calculations have been published yet. Thus, a new iron model
atom has been developed, which includes hydrogen collisions for excitation,
ionization and charge transfer processes. We show that collisions with hydrogen
leading to charge transfer are important for an accurate non-LTE modeling. We
apply our calculations on several benchmark stars including the Sun, the
metal-rich star {\alpha} Cen A and the metal-poor star HD140283.
