Comment on “Thermodynamic optimization of Co-Ge binary system” by S.S. Dong, S.G. Liu, X.M. Tao, F.H. Xiao, L.H. Huang, F. Yang, Y. He, Q. Chen, H.S. Liu, Z.P. Jin [Thermochim. Acta 572 (2013) 94-100]

- It is shown that the sublattice model for βCo5Ge3 is incompatible with the crystal structure.
- A proper sublattice model for βCo5Ge3 is proposed: (Co,Va)1(Co)1(Ge)1.
- It is argued that sublattice models should reflect the crystallographic reality.