Band structure and high pressure study of Rh<Subscript>3</Subscript>Sc, Rh<Subscript>3</Subscript>Y and Rh<Subscript>3</Subscript>La

The electronic structure of the Rhodium based intermetallic compounds (A<Subscript>3</Subscript>B) such as Rh<Subscript>3</Subscript>Sc, Rh<Subscript>3</Subscript>Y and Rh<Subscript>3</Subscript>La are studied by the Self Consistent Tight Binding Linear Muffin Tin Orbital (TB-LMTO) method. In the present work, an attempt has been made to understand why the compounds namely Rh<Subscript>3</Subscript>Y and Rh<Subscript>3</Subscript>La crystallize in hexagonal structure, rather than the cubic structure, where as some of the similar rhodium based A<Subscript>3</Subscript>B compounds namely Rh<Subscript>3</Subscript>Ti, Rh<Subscript>3</Subscript>Zr, Rh<Subscript>3</Subscript>Hf, Rh<Subscript>3</Subscript>V, Rh<Subscript>3</Subscript>Nb, Rh<Subscript>3</Subscript>Ta and Rh<Subscript>3</Subscript>Sc are found to stabilize in cubic structure. In this work a prediction has been made about the structural phase transition in Rh<Subscript>3</Subscript>Y and Rh<Subscript>3</Subscript>La, from Hexagonal phase to Cubic phase. A report of the lattice constant, bulk moduli, cohesive energy and electronic specific heat coefficient is made and is compared with the available experimental data. Band structure and density of states histograms are also plotted. An electronic topological transition is predicted in Rh<Subscript>3</Subscript>La, which may lead to the changes in the Fermi surface topology and hence changes the physical properties of Rh<Subscript>3</Subscript>La. Copyright EDP Sciences/Società Italiana di Fisica/Springer-Verlag 2006