The electronic structure and chemical bonding mechanism of silver oxide

The electronic structure and the chemical bonding mechanism of silver oxide (Ag2O) are studied on the basis of band-structure calculations, using the full-potential linearized augmented-plane-wave (FLAPW) method. Our calculations indicate that silver oxide is a metal (or a semi-metal). Total and partial densities of states and electron densities were calculated and are utilized to give an interpretation of the chemical bonding. The admixture of the Ag 5s states with the Ag 4d-O 2p bands proved to be essential for the covalent bonding effect, since pure 4d-2p bands, with bonding and antibonding states fully occupied, do not lead to a covalent energy gain. It is found that there are significant deviations from a simple ionic picture due to the depletion of the valence band of the Ag 4d electrons, leading to non-spherical charge density around the silver.