Zr I lines in GIRAFFE spectrum of the target RGB star 23821 (dots) overlaid with the synthetic spectrum (grey solid line) computed using T_eff = 4404 K, log g = 1.46, [Fe/H] = -0.76, ?_micro = 1.38 km s^-1, and ?_macro = 4.80 km s^-1. Different panels show the environment of Zr I lines located at 612.7475 nm (left), 613.4585 nm (middle), and 614.3252 nm (right). Red and blue solid lines are synthetic profiles of the individual Zr I and CN lines, respectively.