The geometry optimization of the beginning of the row of FenCm nanoparticles was carried out using the DFT based DMol(3) method. For FeC2 and Fe,C the triangular configurations are found to have the lowest binding energy. The most stable planar structures for FeC3 and Fe2C2 are favored over the three-dimensional isomers, whereas for Fe3C the pyramidal configuration appeared to be the ground state. The effective charges and total spin densities on the atoms were calculated using integral and Mulliken schemes incorporated in DVM and Hirshfeld procedure of DMol(3). The most reasonable values were obtained with the use of integral method. (c) 2005 Elsevier B.V. All rights reserved.