The Einstein-Maxwell field equations in presence of pressure and matter have been considered when the electromagnetic field is nonnull. Every possible structure ofRμλ has been analysed from the point of view of geometry and physics. It has been found that not every geometrically possible solution is admissible from the physical point of view. In every case ℱ,μ, p and the basic vectors have been represented as algebraic concomitants of the contracted curvature tensorRμλ. The method of investigation is based on a method used byHlavatý (3).