A limitation on the pseudopotential method

Self-consistent KKR energy-band calculations for different phases at constant atomic volume show significant differences in the core wavefunctions between f.c.c. and b.c.c. Be. The difference in the core contribution sign to the change in total energy. Since these core contributions are ignored in pseudopotential calculations of phase stability, the pseudopotential method cannot be used with confidence for the prediction of structural stability. © 1976.