Based on density functional theory, the capacities of FeC5H5, Fe2C5H5 and one-dimensional (FeC5H5)(infinity) nanowire as hydrogen storage media were investigated. The results show that FeC5H5 and Fe2C5H5 can adsorb five and ten H-2 molecules, respectively, and form stable FeC5H5(H-2)(5) and Fe2C5H5(H-2)(10) systems. The hydrogen storage capacities of the two systems are 7.63 wt% and 10.15 wt%, while the average adsorption energies are 0.49 and 0.73 eV/H-2, indicating that FeC5H5 and Fe2C5H5 are excellent hydrogen storage media. In addition, (FeC5H5), nanowire can also adsorb H-2 molecules (1.62 wt%). Most importantly, the magnetic and electrical properties of the nanowire are sensitive to the additional H-2, thus (FeC5H5)(infinity) can be used for selecting and detecting H-2 molecules. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.