On algebraically special space-times with twisting rays

The reduced gravitational field equations are derived for algebraically special space-times with twisting geodesic and shear-free rays for a large class of Ricci tensors. These equations coincide with those derived by Trim and Wainwright under more restrictive assumptions on the Ricci tensor. Penrose's conformal technique is used to facilitate computation and interpretation of the results. The remaining coordinate freedom and freedom in the choice of tetrad is discussed. (author)