Abstract
Calcium alanate is a candidate material for high-density reversible solid-state hydrogen storage that thus far has been scarcely studied. This paper presents a scheme for solving the crystal structure of a compound based on only a few model structures from similar compounds and employs this to predict the crystal structure and electronic structure of . By deliberately breaking the symmetry of the model structures down to , local minima may be avoided, and thus the number of required input models is smaller. Density-functional band-structure calculations within the generalized gradient approximation were used in the structural minimizations. The most stable structure was based on and was in the orthorhombic space group with lattice constants , , and . The electronic density of states reveals an insulator with a band gap of around .
- Received 18 January 2005
DOI:https://doi.org/10.1103/PhysRevB.71.144111
©2005 American Physical Society