The superposition model was originally developed to separate the geometrical and physical information in crystal field parameters. Its success in the analysis of lanthanide spectra has been paralleled by the success of the related angular overlap model in the analysis of d-electron spectra. The basic ideas, method of application and reliability of the superposition model are discussed and its relationship with the angular overlap model is clarified. Developments described are the application of the superposition model to the ground (L=0) multiplet splittings of d5 and f7 ions, orbit-lattice interactions, transition intensities and correlation crystal fields. Special attention is paid to work which has been claimed to support or disprove the postulates of the model.

https://iopscience.iop.org/article/10.1088/0034-4885/52/6/002/pdf

The superposition model of crystal fields

The Binary Rare Earth Oxides.

Results of analyses on composite samples of igneous and sedimentary rocks and chondritic meteorites, obtained by an improved analytical procedure, are reported. The relative rare-earth abundances in composite samples of shales, metamorphosed shales, basalts, rhyolites, and granites are remarkably similar to each other, but small differences are apparent, even among the heavier rare earths. Eu and Ce show “anomalous” abundances in several of the samples. A new value for the average Gd content of chondritic meteorites leads to the conclusion that common crustal rocks are deficient in Eu, relative to the other rare earths.

Straight lines can be drawn on comparison diagrams between the elements Pr and Tb in most samples, and between La and Tb (Eu excepted) in some. Equally good lines can be drawn whether rare-earth atomic number, ionic radius, or reciprocal ionic radius is used as the abscissa.

Relative and Absolute Terrestrial Abundances of the Rare Earths

Trace element partition between two pyroxenes and the host lava

Instrumental activation analysis of standard rocks with high-resolution γ-ray detectors☆

/pdf/lattice-parameters-of-some-rare-earth-compounds-and-a-set-of-4bzqjox0j3.pdf

Lattice Parameters of Some Rare Earth Compounds and a Set of Crystal Radii

/pdf/crystal-structures-of-rare-earth-oxychlorides-3t0cmmhh0m.pdf

Crystal Structures of Rare Earth Oxychlorides

/pdf/crystal-structures-of-americium-compounds-49qxs9b8bq.pdf

Crystal structures of americium compounds

/pdf/the-crystal-structure-of-sodium-superoxide1-4ikmuu4tje.pdf

The Crystal Structure of Sodium Superoxide1

/pdf/crystal-structure-and-magnetic-susceptibility-of-americium-4o39sv6t64.pdf

Carol H. Dauben

Papers

Lattice Parameters of Some Rare Earth Compounds and a Set of Crystal Radii

Crystal Structures of Rare Earth Oxychlorides

Crystal structures of americium compounds

The Crystal Structure of Sodium Superoxide1

Crystal structure and magnetic susceptibility of americium metal