New Pseudophase Structure for αPu
Abstract
We propose a new pseudophase crystal structure, based on an orthorhombic distortion of the diamond structure, for the groundstate α phase of plutonium. Electronicstructure calculations in the generalizedgradient approximation give approximately the same total energy for the two structures. Interestingly, our new pseudophase structure is the same as the γPu structure except with very different b/a and c/a ratios. We show how the contraction relative to the γ phase, principally in the z direction, leads to an αlike structure in the [0,1,1] plane and reproduces the short range bonds of the α phase. This is an important link between two complex structures of Pu and opens new possibilities for exploring the very rich phase diagram of Pu through theoretical calculations.
 Publication:

Physical Review Letters
 Pub Date:
 March 2004
 DOI:
 10.1103/PhysRevLett.92.095503
 arXiv:
 arXiv:condmat/0305148
 Bibcode:
 2004PhRvL..92i5503B
 Keywords:

 61.50.Ks;
 64.30.+t;
 64.70.Kb;
 Crystallographic aspects of phase transformations;
 pressure effects;
 Equations of state of specific substances;
 Solidsolid transitions;
 Condensed Matter
 EPrint:
 doi:10.1103/PhysRevLett.92.095503