Ion abundance relative to the Sun (Asplund et al. 2009) of the WASP-178 atmosphere. On the y-axis, N corresponds to the number of atoms of a given ionic species indicated on the x-axis and legend, while N_tot is the total number of atoms. Black open squares show the abundance of the neutral elements, red open diamonds are for singly ionised elements, and blue asterisks are for doubly ionised elements.