Abstract
Recently two high-pressure phases of Ca above 100 GPa have been identified and shown to possess high superconducting critical temperatures . Their crystal structures, however, are unknown. The search for low-enthalpy structures within the stability range using genetic algorithm and quasirandom methods yielded the same solutions. Both methods reveal a structure for Ca-IV and a structure for Ca-V. Calculated diffraction patterns are in substantial agreement with experiments. The proposed structures are both found to be superconducting, and the calculated values are close to those observed for Ca-IV and Ca-V.
- Received 19 October 2007
DOI:https://doi.org/10.1103/PhysRevB.78.054506
©2008 American Physical Society