  We classify algebraic curvature tensors such that the Ricci operator is
simple (i.e. the Ricci operator is complex diagonalizable and either the
complex spectrum consists of a single real eigenvalue or the complex spectrum
consists of a pair of eigenvalues which are complex conjugates of each other)
and which are Jacobi--Ricci commuting (i.e. the Ricci operator commutes with
the Jacobi operator of any vector).
