\label{method} Our stellar models are calculated with a hydrodynamic stellar evolution code. This code can calculate the effect of rotation on the stellar structure, rotationally induced chemical mixing, and the transport of angular momentum by magnetic torques . Compositional mixing is treated as a diffusive process. The rate of change of a nuclear species of mass fraction \(X_i\) is calculated as where \(D\) is the diffusion coefficient constructed from the sum of individual diffusion coefficients for the range of mixing processes \citep[see][and references therein]{hlw00}. The second term on the right hand side is the schematic symbol to stand for all nuclear reactions. The contributions to the diffusion coefficient are convection, semiconvection and thermohaline mixing. For rotating models also the contributions from rotationally induced mixing and magnetic diffusion are computed. The transport of angular momentum is also treated as a diffusive process \cite{es78,pin89,hlw00}.