Ab initio electronic structure calculations of actinide compounds have a weak point when the spin-orbit coupling is treated using a scalar-relativistic basis and the second variational method due to the poor description of the $6p$ states. We extend the basis set of the second variational step by including relativistic $p_{1/2}$ local orbitals for the description of the $6p$ states. Our results show that the additional $p_{1/2}$ local orbitals significantly improve the description of actinides.

• Received 13 June 2001

DOI:https://doi.org/10.1103/PhysRevB.64.153102