To demonstrate the use of diabatic Orbitals in high-spin calculations, the yrast structure of 158Er is calculated and compared to experiment. A very satisfactory reproduction of the observed spectra is obtained from lowest spins through the collective bands up to band terminations. From results like this, a detailed understanding of the orbserved features emerge. In this case, for example, the different alignment properties in negative-parity bands can be understood as due to deformation differences and the existence of additional bands are predicted. Furthermore, the limitations of the cranked mean field approach can be investigated due to the high level of detail in this approach. © 1990.