Electronic structure of the bulk and layers of the alkaline earths (Be-Ba)

TLDR: In this article, the results of electronic structure calculations for the bulk and layers of the alkaline earths (Be-Ba) were made using the linearized muffin-tin orbital method within the local density approximation.

Abstract: We report the results of electronic structure calculations for the bulk and layers of the alkaline earths (Be-Ba) made using the linearized muffin-tin orbital method within the local density approximation. In agreement with experiments, bulk calcium and strontium are found to undergo a metal-semi-metal transition under compression, whereas for each of these elements a single (100) layer is found to have vanishing density of states at the Fermi energy at normal pressure. A layer of Ba, on the other hand, exhibits a similar behaviour under expansion. As compared to the bond length for the bulk, there is an expansion for a single layer in all of the cases. This expansion is large for Mg, which is consistent with the large bond length of the Mg dimer. The binding energy for a single layer is close to its value for dimers but it increases by a large amount for three layers. These results are discussed in terms of the changes in the s-p/d hybridization with the reduction in the coordination, and its importance for understanding the properties of clusters of transition metals.