To overcome this problem the sample is spun at the magic angle, 54.74 degrees. This can lead to peaks that are extremely broad with linewidths greater than 1000 Hz. In a solid-state powder sample every orientation of the sample relative to the external magnetic field is present. In liquid-state NMR the rapid rotation of a molecule in solution averages out the chemical shift to a single value called the isotropic chemical shift. The chemical shift that a molecule has for a particular nucleus is a function of alignment of the molecule to the external magnetic field. The Discovery system is capable of running CP/MAS experiments using a 4 mm rotor. The Shared Instruments Lab currently operates one solid-state NMR, a 2-channel 400 MHz Tecmag Discovery with a NMR Service GmbH MAS H-X broadband probe that can rotate samples up to 18 kHz. programĪpproval of dissertation and final oral examination Time limitation for completion of advanced degreesĪdmission to chemical physics from an M.S. Graduate record examination scores and transcripts Graduate student evaluation proceduresĮntry into the Graduate Program in Chemical Physics Entry into the graduate program in chemistryį.
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