  Until recently, spin-polarization in nonmagnetic materials was the exclusive
territory of non- centrosymmetric structures. It was recently shown that a form
of hidden spin polarization (named the Rashba-2 or R-2 effect) could exist in
globally centrosymmetric crystals provided the individual layers belong to
polar point group symmetries. This realization could considerably broaden the
range of materials that might be considered for spin-polarization spintronic
applications to include the hitherto forbidden spintronic compound that belong
to centrosymetric symmetries. Here we take the necessary steps to transition
from such general, material-agnostic condensed matter theory arguments to
material-specific design principles that could aid future laboratory search of
R-2 materials. Specifically, we (i) classify different prototype layered
structures that have been broadly studied in the literature in terms of their
expected R-2 behavior, including the Bi2Se3-structure type (a prototype
topological insulator), MoS2-structure type (a prototype valleytronic compound)
and LaBiOS2-structure type (a host of superconductivity upon doping); (ii)
formulate the properties that ideal R-2 compounds should have in terms of
combination of their global unit cell symmetries with specific point group
symmetries of their constituent sectors; (iii) use first-principles band theory
to search for compounds from the prototype family of LaOBiS2-type structures
that satisfy these R-2 design metrics. We initially consider both stable and
hypothetical compounds to establish an understanding of trends of R-2 with
composition, and then indicate the predictions that are expected to be stable
and synthesizable. We predict large spin splittings (up to ~ 200 meV for holes
in LaOBiTe2) as well as surface Rashba states. Experimental testing of such
predictions is called for.
