Stability of orthorhombic MgSiO3 perovskite in the earth's lower mantle.

Studies the stability of orthorhombic magnesuim-rich silicate perovskite (MgSiO3) in the Earth's lower mantle. Results of electronic-structure calculations of the energetics of displacive phase transitions in MgSiO3 perovskite; Demonstration that the lower-symmetry orthorhombic phase should be highly favored throughout the lower mantle.