We study from first principles the electronic, structural, dielectric, and dynamical properties of the hexagonal and orthorhombic structures of K2 Se O4. The two ideally ordered high- T hexagonal phases are a model for many other phases of this compound, obtained by slight distortions of these highly symmetric structures. We determine the lattice and atomic parameters of these phases, and describe their band structure. All the structures present zone-center dynamical instabilities. We compare the zone-center vibrational frequencies with the available experimental data.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 2006|