Of Molecular Structure and Spectra

Hartree-Fock (HF), molecular orbital theory satisfies most of the criteria, but qualitative failures and quantitative discrepancies with experiment often render it useless. Methods that systematically account for electron correlation, employed in pursuit of more accurate predictions, often lack a consistent, interpretive apparatus. Among these methods, electron propagator theory [1] is distinguished by its retention of many conceptual advantages that facilitate interpretation of molecular structure and spectra [2, 3, 4, 5, 6, 7, 8, 9]. 

Sigeru Huzinaga, one of the pioneers in the development of Gaussian basis sets for molecular calculations, held the position of associate professor in physics at Kyushu University in the 1960s. During that time he was invited by R. S. Mulliken to join the research group at the Laboratory of Molecular Structure and Spectra at the Department of Physics of the University of Chicago, where, under Mulliken and C. C. J. Roothaan, he participated in the inception of computational quantum chemistry (1959-1961). He was appointed professor of chemistry at the University of Alberta in 1968. 

Technical Report, Laboratory of Molecular Structure and Spectra, Department of Physics,... 

QUANTUM CHEMISTRY AND THE LABORATORY OF MOLECULAR STRUCTURE AND SPECTRA, CHICAGO, 1960... 

This research was supported in part by the National Science Foundation, Grant No. GP-3698. S.-I.K. wishes to express sincere appreciation to the University of Utah Research Committee for the fellowship granted to him and also to Dr. Juergen A. Hinze of the Laboratory of Molecular Structure and Spectra, Department of Physics, The University of Chicago, for reading and commenting on this manuscript. 

Recently, due to both availability of the Fourier transform VCD spectrometers (FT-VCD) and DFT software for predicting the VCD spectra, the VCD technique has become widely recognized and used [108-110]. DFT has been accepted by the ab initio quantum chemistry community as a cost-effective approach to computations of molecular structures and spectra (vibrational and NMR) of molecules of chemical interest. Many studies have shown that vibrational frequencies and VCD intensities calculated by means of DFT methods are more reUable than those obtained at the MP2 level [87]. 

Individual and institutional ties with American scientists, universities, and organizations were a distinctive feature of Lowdin s career Slater acted as his mentor the organization of both Mulliken s Laboratory of Molecular Structure and Spectra and Slater s Solid-State and Molecular Theory Group inspired the creation and organization of the Quantum Chemistry Group. American agencies sponsored the group s activities. 

Bernard]. Ransil (born 1929) obtained his Ph.D. in 1955 at the Catholic University in Washington, D. C., for work on the LCAO-MO-SCF treatment of the H3 molecule. One year later, he became a research associate at the Laboratory of Molecular Structure and Spectra, replacing Roothaan who was on leave in Europe on a Fulbright Scholarship and doing work that led to the first generation of machine programs. A group of... 

Beynon, J.H. Correlation of Molecular Structure and Mass Spectra, in Mass Spectrometry and its Applications to Organic Chemistry, 1st ed. Elsevier Amsterdam, 1960 pp. 352. 

B. R. Henry, Acc. Chem. Res., 20, 429 (1987). The Local Model and Overtone Spectra A Probe of Molecular Structure and Conformation. 

Reuben J (1984) Isotopic multiplets in the carbon-13 NMR spectra of polyols with partially deuterated hydroxyls. Fingerprints of molecular structure and hydrogen bonding effects in the 13C NMR spectra of monosaccharides with partially deuterated hydroxyls. J Am Chem Soc 106 6180-6186... 

The first theoretical studies on AI2O3 were of electronic structure and spectra. Photoelectron studies on AI2O3 (Balzarotti and Bianconi, 1976 Gignac et a ., 1985) show a two-peak O 2p valence band with a peak separation of 4-4.7 eV and an overall width of about 8.5 eV (Fig. 4.7). Cluster calculations using the MS-SCF-Aa method (Tossell, 1975a), and the semi-empirical molecular-orbital EHMO (Ciraci and Batra, 1983) and CNDO... 

In 1955, I attended the first of the Summer Schools in Theoretical Chemistry, organised by Charles Coulson, then Rouse-Ball Professor of Mathematical Physics at Oxford, to introduce young chemists to the Molecular Orbital (MO) Theory, to which he made outstanding contributions. The MO theory gave me a wider perspective for the interpretation of molecular spectra and the study of molecular structures and reaction mechanisms. 

There is no limit to the complexity of molecular structures and thus, it is clear that NMR spectra can become ever more complicated. In large molecules such as proteins, the second dimension is often not enough to provide the necessary resolution for facile interpretation. This has lead to the development of... 

G. Herzberg and J. W. C. Johns, Symposium on Molecular Structure and Spectra, Ohio State University, 1963. G. Herzberg, "The Spectra and Structure of Simple Free Radicals", Cornell University Press, Ithaca (1971). 

As stated in Section 7-8, on those occasions when (i) the C spectrum is more congested than the H spectrum and (ii) a sufficient amount of the sample ( 20 mg for MW 400-750) can be dissolved to obtain C spectra in reasonable time, FLOCK spectra can be indispensable in the elucidation of molecular structures and the assignment of chemical shifts. 

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