Comment on “High-temperature superconductivity in transition metallic hydrides MH11 (M = Mo, W, Nb, and Ta) under high pressure” by M. Du, Z. Zhang, H. Song, H. Yu, T. Cui, V. Z. Kresinc and D. Duan, Phys. Chem. Chem. Phys., 2021, 23, 6717

In superconductors, scattered electrons cover the entire surface of the Fermi sphere (circle in the figure, valency = 3). In the MP scheme in the article concerned, the shaded wedge confines coverage, causing errors in results.