Evolution of the Ti L₂₃ edge across an atomically resolved SrTiO₃(STO)/PbTiO₃(PTO) interface (a) HADF image; (b) selection of six EELS spectra of the Ti L₂₃ edge, each one built as the addition of 8 × 8 individual spectra recorded over the red squares shown in (a) [65]; (c) reference spectra recorded on larger areas of STO (black) and PTO (red); (d) ab initio and multiplet calculations of the L lines profiles demonstrating a reduced t_2g-e_g splitting of the L₃ line from the cubic STO cell to the tetragonally distorted PTO cell [70].