Electronic structure and geometry optimization of nanoparticles Fe2C, FeC2, Fe3C, FeC3 and Fe2C2

The geometry optimization of the beginning of the row of FenCm nanoparticles was carried out using the DFT based DMol3 method. For FeC2 and Fe2C 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 DMol3. The most reasonable values were obtained with the use of integral method.