  In this study, using the concept of relative entropy as a distance measure of
cor- relations we investigate the important issue of evaluating quantum
correlations such as entanglement, dissonance and classical correlations for
2n-dimensional Bell-diagonal states. We provide an analytical technique, which
describes how we find the closest classical states(CCS) and the closest
separable states(CSS) for these states. Then analytical results are obtained
for quantum discord of 2n-dimensional Bell-diagonal states. As illustration,
some special cases are examined. Finally, we investigate the additivity
relation between the different correlations for the separable generalized bloch
sphere states.
