The electronic and magnetic properties, as well as the optical properties of NaS
and NaSe compounds have been conducted using first-principles calculations based
on density-functional theory (DFT) and FP-LAPW method. The
Perdew–Burke–Ernzerhof generalized gradient approximation (PBE-GGA) and
modified Becke-Johnson (mBJ-GGA) have been used to deal with the exchange-
correlation potential. The PBE-GGA and mBJ-GGA electronic calculation of the
spin-up configuration shows an insulating behavior, while the spin-down shows a
metallic behavior. In addition, both PBE-GGA and mBJ-GGA agree that the total
magnetic moment per unit cell for these compounds is 1μ B . From optical calculations
we see that ε 1 (0) value in the spin up channel is positive which shows an insulating
character, while for the spin-down configuration it has a large negative value, which
shows a metallic character. The NaS and NaSe refractive index indicates a metallic
demeanor as the real and imaginary dielectric constant.