−0.5 d NIR spectrum of SN 2021hem obtained with the NASA IRFT telescope equipped with SpeX. The prominent identified lines are labeled. The vertical red, green, and blue lines mark the positions for O I, Mg II, and C I lines respectively, where all lines for a given atomic species are at the same velocity. The O I (red) λ0.7774, λ0.9266 μm lines are at 10 500 km s⁻¹, Mg II (green) λλ0.9218, 0.9244, λ0.9632, λ1.0092, λ1.0927 μm lines are at 11 700 km s⁻¹, and C I (blue) λ0.9093, λ0.9406, λ1.0693, λ1.1754 μm lines are at 12 500 km s⁻¹. Strong lines of Mg II and O I are identified, whereas for C I no prominent line identification is found, the C I line positions are shown at a tentative velocity of ≈12 500 km s⁻¹.