CR $Q$-curvature and CR pluriharmonic functions

In this paper, we show that the CR $Q$-curvature is orthogonal to the space of CR pluriharmonic functions on any closed strictly pseudoconvex CR manifold of dimension at least five. To this end, we obtain a cohomological expression of the integral of the product of the CR $Q$-curvature and a CR pluriharmonic function.