Fig. 2: Phonon dispersion of Na2CoSe2O.

a Anharmonically renormalized phonon dispersions at finite temperatures (from T = 300–900 K). Viridis colorbar indicates temperatures. Pink ellipses indicate acoustic-optical bunching. b Atomic projected dispersions at 300 K by Na, O, Co, and Se atoms. Plasma colorbars represent the atomic contribution to each mode at each eigenvector normalized to 1.