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Lattice Frequencies and Rotational Barriers for Inorganic Carbonates and Nitrates From Low Temperature Infrared Spectroscopy (Record no. 1177)

MARC details
042 ## - AUTHENTICATION CODE
Authentication code dc
100 10 - MAIN ENTRY--PERSONAL NAME
Personal name Schroeder, R. A.
Relator term author
9 (RLIN) 391
245 00 - TITLE STATEMENT
Title Lattice Frequencies and Rotational Barriers for Inorganic Carbonates and Nitrates From Low Temperature Infrared Spectroscopy
260 ## - PUBLICATION, DISTRIBUTION, ETC.
Name of publisher, distributor, etc. National Institute of Standards and Technology,
Date of publication, distribution, etc. 1962.
500 ## - GENERAL NOTE
General note /pmc/articles/PMC6696536/
520 ## - SUMMARY, ETC.
Summary, etc. Infrared absorption spectra of inorganic nitrates and carbonates have been obtained on single crystals at room temperature, under liquid nitrogen refrigeration and under liquid helium refrigeration. Diffuse absorption observed in the room temperature spectra between about 1400 cm(−1) and 700 cm(−1) is resolved under liquid helium refrigeration into a large number of bands not attributable to fundamentals or combinations of fundamental frequencies of the anions. Almost all of these bands are readily interpreted as summation bands of fundamental frequencies with successive levels of a librating oscillator. The libration is considered to represent a planar torsional oscillation of the anion about the trigonal axis. The librational frequency depends in part on the crystal structure and on the ions. In a given material the librational frequency as determined from successive bands is reasonably constant. In the substances studied the librational frequency varied from about 15 cm(−1) to 30 cm(−1). Band limits observed in the spectra are interpreted as representing rotational energy barriers. These barrier heights are approximately 200 cm(−1) with some dependence on the crystal structure and the ions involved. Barrier heights calculated from a cosine potential function agree reasonably well with the observed barriers for the cubic and calcite structures. Similar calculations have not been made for other structures studied because of doubtful assignments or unknown structural details. In particular, spectra of the aragonite structures are remarkable in detail and complexity, and have not been analyzed. However, the details of these and all other spectra studied appear to involve similar phenomena.
540 ## - TERMS GOVERNING USE AND REPRODUCTION NOTE
Terms governing use and reproduction
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Language note en
690 ## - LOCAL SUBJECT ADDED ENTRY--TOPICAL TERM (OCLC, RLIN)
Topical term or geographic name as entry element Physics and Chemistry
655 7# - INDEX TERM--GENRE/FORM
Genre/form data or focus term Text
Source of term local
700 10 - ADDED ENTRY--PERSONAL NAME
Personal name Weir, C. E.
Relator term author
700 10 - ADDED ENTRY--PERSONAL NAME
Personal name Lippincott, E. R.
Relator term author
9 (RLIN) 393
786 0# - DATA SOURCE ENTRY
Note J Res Natl Bur Stand A Phys Chem
856 41 - ELECTRONIC LOCATION AND ACCESS
Uniform Resource Identifier <a href="http://dx.doi.org/10.6028/jres.066A.042">http://dx.doi.org/10.6028/jres.066A.042</a>
Public note Connect to this object online.

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