Negativity and tight constraints of multiqubit entanglement

We provide a characterization of multiqubit entanglement constraints in terms of negativity. By using the square of convex-roof extended negativity (SCREN) and the Hamming weight of the binary vector related with the distribution of subsystems, we show that the alpha th power of SCREN provides a class of monogamy inequalities of multiqubit entanglement in a tight way for alpha >= 1. We further show that the beta th power of SCREN also provides a class of tight polygamy inequalities for 0 <= beta <= 1.