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Understand the meaning of resolution and completeness in crystal lattice analysis with autoindexing. Learn about the 9 key parameters provided by autoindexing and the importance of the A matrix. Discover the practical guide to crystal indexing and inverse beam anomalous scattering.
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What does autoindexing tell you? For a given crystal lattice: Every possible reflected x-ray beam is assigned a unique index: (h,k,l)
What does autoindexing tell you? 9 numbers:
What does autoindexing tell you? 9 numbers: 3 cell edge lengths (Ǻngstroms)
What does autoindexing tell you? 9 numbers: 3 cell edge lengths (Ǻngstroms) 3 cell corner angles (degrees)
What does autoindexing tell you? 9 numbers: 3 cell edge lengths (Ǻngstroms) 3 cell corner angles (degrees) 3 crystal rotations (degrees)
What does autoindexing tell you? 9 numbers: 3 cell edge lengths (Ǻngstroms) 3 cell corner angles (degrees) 3 crystal rotations (degrees)
What does autoindexing tell you? 9 numbers: 3 cell edge lengths (Ǻngstroms) 3 cell corner angles (degrees) 3 crystal rotations (degrees) The “A” matrix
What does autoindexing tell you? 9 numbers: 3 cell edge lengths (Ǻngstroms) 3 cell corner angles (degrees) 3 crystal rotations (degrees) A = B · u
What does autoindexing tell you? 9 numbers: 3 cell edge lengths (Ǻngstroms) 3 cell corner angles (degrees) 3 crystal rotations (degrees) A · (hkl) = (xyz)
Anomalous Scattering X-rays wavelenghts are far above the natural frequencies of most atomic transitions
Anomalous Scattering X-rays wavelenghts are far above the natural frequencies of most atomic transitions All atoms normally scatter in phase
Anomalous Scattering X-rays wavelenghts are far above the natural frequencies of most atomic transitions All atoms normally scatter in phase Each spot is the sum of the scattered radiation from each atom
Anomalous Scattering X-rays wavelenghts are far above the natural frequencies of most atomic transitions All atoms normally scatter in phase Each spot is the sum of the scattered radiation from each atom The different locations of atoms in the unit cell cause slight differences in scattered ray “path lengths”
Anomalous Scattering X-rays wavelenghts are far above the natural frequencies of most atomic transitions All atoms normally scatter in phase Each spot is the sum of the scattered radiation from each atom The different locations of atoms in the unit cell cause slight differences in scattered ray “path lengths” The different path lengths cause interference
Anomalous Scattering X-rays wavelenghts are far above the natural frequencies of most atomic transitions All atoms normally scatter in phase Each spot is the sum of the scattered radiation from each atom The different locations of atoms in the unit cell cause slight differences in scattered ray “path lengths” The different path lengths cause interference
Anomalous Scattering X-rays wavelenghts are far above the natural frequencies of most atomic transitions All atoms normally scatter in phase Each spot is the sum of the scattered radiation from each atom The different locations of atoms in the unit cell cause slight differences in scattered ray “path lengths” The different path lengths cause interference
Anomalous Scattering X-rays wavelenghts are far above the natural frequencies of most atomic transitions All atoms normally scatter in phase Each spot is the sum of the scattered radiation from each atom The different locations of atoms in the unit cell cause slight differences in scattered ray “path lengths” The different path lengths cause interference Each spot has a unique amplitude and phase
