To try to grow CsEuP 2 O 7 crystals, we replaced the lanthanide precursor with europium compounds for several solution and solidstate synthesis procedures for isostructural lanthanide compounds. None of the procedures returned a phase containing Cs, Eu, P, and O. Both solid-state procedure products contained EuPO 4 , with one including a small EuPO 4 crystal. The crystal's PL emission spectrum, with a The room temperature PL emission spectrum of Cs 2 NaEuF 6 shows each of the 5 D 0 → 7 F J (J = 0-4) transitions. The inset shows the weak J = 0 transition next to the much higher intensity J = 1 transition and its shoulder peaks. sharp 5 D 0 → 7 F 0 transition matching a previous study is in the Supporting Information along with additional synthesis attempt details.