Crystal structures and electronic properties of MC2 (MÂ =Â Mg, Ca, Sr, Ba) by comparative studies based on ab-initio calculations

A theoretical study of MC2's band structures and electronic properties. The chemical bonds are admixed with an ionic bond between M2+ and C22- and a strong covalent bond in anion clusters. Orbital hybridization effect is more evident with small ionic radius and atomic number, which lead the structure I4/mmm to P42/mnm. Relatively flat dispersion relations of band structures are indicated the localized bonding state and population analysis provided further information on this aspect. After analyzing the DOS, the valence band near the EF are all dominated by 2p orbit of carbon atoms and metals are important for conduction band.