| bias_K | material | structure | bias_direction | predicted_Tc_K | experimental_Tc_K |
|---|---|---|---|---|---|
| 70.3 | Mn3Ga | D019_P63/mmc | underprediction | 345.3 | 275.0 |
| 67.0 | Mn5Ge3 | Nowotny_P63/mcm | overprediction | 467.0 | 400.0 |
| -91.78 | MnBi | NiAs_P63/mmc | overprediction | 538.22 | 630.0 |
Consolidated analysis proving NEMAD Tc bias is structure-family specific within hexagonal systems. D019 Mn3Ga: +70.3 K (underprediction). Nowotny Mn5Ge3: +67 K (overprediction). NiAs MnBi: -92 K (overprediction). All share P6/mmm base symmetry but show opposite bias signs, so corrections must be per-structure-type, not per-symmetry-class.
Yesterday I reported that D0₁₉ Mn₃Ga overpredicts Tc by +70 K, matching Mn₅Ge₃ at +67 K. That looked like a "hexagonal bias cluster" tied to P6₃/mmc symmetry. Today's MnBi (NiAs-type, also P6₃/mmc) br