Theory of pressure-induced phase transitions in cerium chalcogenides

The electronic structures of the cerium chalcogenides CeS, CeSe, and CeTe are studied using the self-interaction corrected local spin-density approximation. This method allows for either a localized or an itinerant description of the cerium f electrons. The observed equilibrium lattice constants and bulk modulii are well reproduced assuming a trivalent cerium configuration. Pressure induced phase transitions ari associated with the delocalization of the f electrons. The observed transitions are quantitatively reproduced in the calculation, and high-pressure phase transitions are predicted. The calculations provide a unifying picture of the cerium chalcogenides under pressure. [S0163-1829(99)01921-6].