Molecular Structure and Infrared Spectra of Dimethyl Fumarateelectronic Supplementary Information (Esi) Available: Definition of Internal Symmetry Coordinates, Calculated Frequencies, Ir Intensities, Raman Activities, Potential Energy Distributions and Optimized Conformers I, Ii and Iii. See Http://Www.rsc.org/Suppdata/Cp/B2/B203246P/