Measure of nonclassical correlation in coherence-vector representation

We consider the coherence-vector representation of a bipartite state and obtain a necessary and sufficient condition for a zero-discord state. Based on this, a measure of quantum, classical, and total amount of correlations in bipartite states is proposed in this representation. Analytical expressions for this measure are available for any bipartite states. Our measure of nonclassical correlation coincides with the geometric measure of quantum discord for some particular states.