Ab initiodetermination of the ground-state properties ofCa2MgSi2O7åkermanite

Abstract
We study from first-principles Ca2MgSi2O7 åkermanite within the local density approximation (LDA) of the density-functional theory. The electronic band structure is formed by weakly dispersive bands, with a 4.2 eV LDA gap. We report the crystal structure, dielectric properties and we compare them with the available experimental data. We also perform a full analysis of all the zone-center vibration modes, in terms of symmetry and vibrational pattern.