  Spin-orbit coupling (SOC), the core of numerous condensed-matter phenomena
such as nontrivial band gap, magnetocrystalline anisotropy, etc, is generally
considered to be appreciable only in heavy elements, detrimental to the
synthetization and application of functional materials. Therefore, amplifying
the SOC effect in light elements is of great importance. Here, focusing on 3d
and 4d systems, we demonstrate that the interplay between crystal symmetry and
electron correlation can dramatically enhance the SOC effect in certain
partially occupied orbital multiplets, through the self-consistently reinforced
orbital polarization as a pivot. We then provide design principles and
comprehensive databases, in which we list all the Wyckoff positions and site
symmetries, in all two-dimensional (2D) and three-dimensional crystals that
potentially have such enhanced SOC effect. As an important demonstration, we
predict nine material candidates from our selected 2D material pool as
high-temperature quantum anomalous Hall insulators with large nontrivial band
gaps of hundreds of meV. Our work provides an efficient and straightforward way
to predict promising SOC-active materials, releasing the burden of requiring
heavy elements for next-generation spin-orbitronic materials and devices.
