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 $\alpha \mathrm{th}$ power of SCREN provides a class of monogamy inequalities of multiqubit entanglement in a tight way for $\alpha \ge 1$. We further show that the $\beta \mathrm{th}$ power of SCREN also provides a class of tight polygamy inequalities for $0\le \beta \le 1$.