Gravitational field of radiating non-twisting charged systems

The Newman–Penrose spin coefficient formalism is used to obtain in explicit form all solUtions of the Einstein–Maxwell equations with thermodynamic radiation (i.e., radiation of Isaacson type) under the conditions that: 1) the radiation propagates along a geodesic congruence determined by the principal isotropic direction of the Maxwell tensor; 2) this congruence is a non-twisting, shear-free diverging congruence; 3) the spacetime has no angular singuiarities or background (low-frequency) gravitational waves.