The molecular structure of N,N’,N "-tris(neopentyl)-1,3,5-triazane is shown by a crystal X-ray diffraction study to have one axial and two equatorial neopentyl groups with eclipsing of both axial and equatorial exocyclic N-CH2 bonds. In solution at about -130 degrees C both ring inversion and nitrogen inversion are slow on the NMR time scale, and 91% of molecules adopt that structure while 9% adopt the ah-equatorial arrangement. The usefulness and shortcomings of molecular mechanics calculations of the structure are shown.