W-Class States-Identification and Quantification of Bell-CHSH Inequalities' Violation.

We discuss a family of W-class states describing three-qubit systems. For such systems, we analyze the relations between the entanglement measures and the nonlocality parameter for a two-mode mixed state related to the two-qubit subsystem. We find the conditions determining the boundary values of the negativity, parameterized by concurrence, for violating the Bell-CHSH inequality. Additionally, we derive the value ranges of the mixedness measure, parameterized by concurrence and negativity for the qubit-qubit mixed state, guaranteeing the violation and non-violation of the Bell-CHSH inequality.