Reply to the Correspondence on "K2 Sb(P2 O7 )F: Cairo Pentagonal Layer with Bifunctional Genes Reveal Optical Performance".

In their Correspondence, Sergey V. Krivovichev and Luca Bindi argue that the novel excellent nonlinear optical material antimony pyrophosphate, K2 Sb(P2 O7 )F, reported in our Research Article published in this journal belongs to the fresnoite Ba2 [TiO(Si2 O7 )] group and its structure is not novel in terms of either topology or local coordination geometry around Sb3+ cations. We clarify that the statements regarding structural features of our original paper are valid in context.