The compound K 2 TiCr(PO 4 ) 3 was predicted to exist as a new cubic phase in the space group P 2 1 3. Fig. ) shows our refinement of the provided PXRD pattern, using known cubic K 2 Ti 2 (PO 4 ) 3 (P 2 1 3; ICSD # 202888) and Cr 2 O 3 , a common impurity in high temperature synthesis of oxides containing chromium. The refinement provided in the A-lab paper had several unfitted peaks, which all correspond to the Cr 2 O 3 impurity phase as marked by red arrows in Fig. ). The example of K 2 TiCr(PO 4 ) 3 shows that there are serious issues with the supposed synthesis of the phosphates, in fact we could index and preliminarily match all 18 PXRD patterns to materials that are reported in the ICSD (see Table in the supplemental information). We consider it to be the responsibility of the authors of the A-lab paper 4 to unambiguously prove the synthesis of the target materials in all cases and will refrain from providing alternative refinements of all 43 materials in this comment. We will however discuss each compound and possible alternatives briefly below.