A generalized constant coupling approximation for quantum geometrically
frustrated antiferromagnets is presented. Starting from a frustrated unit, we
introduce the interactions with the surrounding units in terms of an internal
effective field which is fixed by a self consistency condition. Results for the
static magnetic susceptibility and specific heat are compared with previous
results in the framework of this same model for the classical limit. The range
of applicability of the model is discussed.Comment: 11 pages, 6 figures, 1 Tables, typeset using RevTeX 4, small
correction in Table