Looks like nobody provided full structural data for this composition. You can start from MoSi2 for C11b, CrSi2 for C40 and TiSi2 for C54. All these structures are available at crystallography.net. Then place correct atoms in all positions and take lattice parameters from your article.
In fact, absence of such data means good news for you. You have a chance to publish them yourself and receive recognition from the future researchers in your field.