  Optimal measurement is required to obtain the quantum and classical
correlations of a quantum state, and the crucial difficulty is how to acquire
the maximal information about one system by measuring the other part; in other
words, getting the maximum information corresponds to preparing the best
measurement operators. Within a general setup, we designed a variational hybrid
quantum-classical (VHQC) algorithm to achieve classical and quantum
correlations for system states under the Noisy-Intermediate Scale Quantum
(NISQ) technology. To employ, first, we map the density matrix to the vector
representation, which displays it in a doubled Hilbert space, and it's
converted to a pure state. Then we apply the measurement operators to a part of
the subsystem and use variational principle and a classical optimization for
the determination of the amount of correlation. We numerically test the
performance of our algorithm at finding a correlation of some density matrices,
and the output of our algorithm is compatible with the exact calculation.
