Effects of Pressure on Chemical Bonding and Mineralogy 
Inside Earth and other Planets 

Raymond Jeanloz
Department of Earth and PLanetary Science
University of California, Berkeley

ABSTRACT

Million-atmosphere pressures, typical of planetary interiors, induce 
dramatic changes in valence-electron energies (eV) of materials, 
hence in physical and chemical properties controlling the evolution 
of planets.  A recently discovered electron-spin transition is one 
example pertaining to the Earth's lower mantle.  New experimental 
methods are opening the realm of billion-atmosphere pressures, 
relevant to super-giant planets or brown dwarfs, and involving 
core-electron energy (keV) changes in materials.