First principles description of the paramagnetic insulating state of chromia

We have investigated the electronic and structural properties of chromia (C r2O3), a typical Mott-Hubbard insulator. We considered the T = 0 K antiferr omagnetic insulating ground state and the paramagnetic insulating state abo ve the Neel temperature (T-N). Our treatment of the latter resembles in pri nciple a virtual crystal model of the random spins insulator and describes reasonably well the compressive behavior of chromia above and the structura l anomalies across T-N. (C) 2001 American Institute of Physics.