[Cu/Fe] versus [Fe/H]. The left panel shows the LTE abundances from the literature, while the middle and right panels show non-LTE abundances using the hydrogen collision data from Belyaev et al. (2021) and our newly calculated LCAO+Free data, respectively. We again overplotted the same GCE model from Kobayashi et al. (2020). Literature data from: Delgado Mena et al. (2017) (dwarfs and subgiants in the thin disc as magenta downwards triangles; thick disc and high-alpha metal-rich disc as light blue squares); Yan et al. (2016) (dwarfs and subgiants in the thick disc as tan squares; high-alpha halo as dark blue circles; low-alpha halo as upwards red triangles); Korotin et al. (2018) (metal-poor dwarfs as magenta open circles); Sneden et al. (2023) (metal-poor dwarfs as light red diamonds); and Caffau et al. (2023) (metal-poor giants as black filled circles).