I am calculating a short fiber reinforced component. I want to read the mapped orientation tensor from Ansys. The eigenvectors of the orientation tensor are the principal directions of the anisotropy (Element Orientation) and the eigenvalues describe the proportion of fibers in the three principal directions (Material Field).  These eigenvalues are stored in the Workbench under Materials/Imported Material Fields. With an APDL code I want to save these material fields automatically. 
I have managed the export of the principal directions (Element Orientation) with APDL. With the GET command *GET Preprocessing Items, Entity = CDSY
But now I am looking for the *GET command for the export of the eigenvalues (Material Field).