Gross atomic structure of Nd III arising from the excitation of one 4f electron, 4f³(^ML)nl for nl = 5d, 6s, 6p, 7s, 6d, and 5f, in relation with the LS terms of the Nd IV ground configuration 4f³. All levels are labelled according to the configurations and parent terms of their leading eigenvector components calculated in the present work using the Cowan code. The extent of each box merely shows the range of level energies within a given 4f³ (^ML)nl sub-configuration. The Nd III ionisation potential (shown by the horizontal black line) is from Johnson & Nelson (2017) and the Nd IV 4f³ term energies are from Wyart et al. (2007).