The Newman-Penrose Weyl scalars are a set of 5 complex scalars, labeled ${\mathrm{\Ψ}}_0$, ${\mathrm{\Ψ}}_1\,$${\mathrm{\Ψ}}_2\,$${\mathrm{\Ψ}}_3\,$${\mathrm{\Ψ}}_4$, and defined by certain components of the Weyl tensor with respect to a given null tetrad in a four dimensional spacetime of signature [1, -1, -1, -1]. Under local Lorentz transformations, the Newman-Penrose Weyl scalars transform among themselves in a natural way. Depending upon the Petrov type of the spacetime it is possible to transform the Newman-Penrose Weyl scalars to one of following normal forms. Below, $\mathrm{\η}$and $\mathrm{\χ}$are complex scalars.$$See NPCurvatureScalars, NullTetradTransformation.