Wave molecular

Vaughan, D. J., Tossell, J. A. Johnson, K. H. (1974) The bonding of ferrous iron to sulfur to sulfur and oxygen in tetrahedral coordination A comparative study using SCF-Xa-scattered wave molecular orbitals calculations. Geochim. Cosmochim. Acta, 38, 993-1005. 

Wolf, K., Mikenda, W., Nusterer, E., Schwarz, K., and Ulbricht, C., Proton transfer in malonaldehyde an ab initio projector augmented wave molecular dynamics study, Chem. Eur. J., 4, 1418-1427 (1998). 

L. Clouser and W. Gordy, Phys. Rev. 134, A863 (1964). Millimeter-Wave Molecular-Beam Spectroscopy Alkali Chlorides. 

F.C. de Lucia, W. Gordy Millimeter and Submillimeter Wave Molecular Beam Masers , in Proc. Symp. Submill. Waves, Microwave Research Institute Symposia Series Vol. XX, ed. by J. Fox (Polytechnic Press, New York 1970)... 

R.J. Butcher, R.B. Dennis, S.D. Smith The tunable spin-flip Raman laser. II. Continuous wave molecular spectroscopy. Proc. Roy. Soc., London A344y 541 (1975)... 

Small metal clusters are also of interest because of their importance in catalysis. Despite the fact that small clusters should consist of mostly surface atoms, measurement of the photon ionization threshold for Hg clusters suggest that a transition from van der Waals to metallic properties occurs in the range of 20-70 atoms per cluster [88] and near-bulk magnetic properties are expected for Ni, Pd, and Pt clusters of only 13 atoms [89] Theoretical calculations on Sin and other semiconductors predict that the stmcture reflects the bulk lattice for 1000 atoms but the bulk electronic wave functions are not obtained [90]. Bartell and co-workers [91] study beams of molecular clusters with electron dirfraction and molecular dynamics simulations and find new phases not observed in the bulk. Bulk models appear to be valid for their clusters of several thousand atoms (see Section IX-3). 

The miderstanding of molecular motions is necessarily based on quaiitum mechanics, the theory of microscopic physical behaviour worked out in the first quarter of the 20th century. This is because molecules are microscopic systems in which it is impossible—or at least very dangerous —to ignore the dual wave-particle nature of matter first recognized in quaiitum theory by Einstein (in the case of classical waves) and de Broglie (in the case of classical particles). 

Much of the previous section dealt with two-level systems. Real molecules, however, are not two-level systems for many purposes there are only two electronic states that participate, but each of these electronic states has many states corresponding to different quantum levels for vibration and rotation. A coherent femtosecond pulse has a bandwidth which may span many vibrational levels when the pulse impinges on the molecule it excites a coherent superposition of all tliese vibrational states—a vibrational wavepacket. In this section we deal with excitation by one or two femtosecond optical pulses, as well as continuous wave excitation in section A 1.6.4 we will use the concepts developed here to understand nonlinear molecular electronic spectroscopy. 

Scherer N F, Carlson R J, Matro A, Du M, Ruggiero A J, Romero-Rochin V, Cina J A, Fleming G R and Rice S A 1991 Fluorescence-detected wave packet interferometry time resolved molecular spectroscopy with sequences of femtosecond phase-locked pulses J. Chem. Rhys. 95 1487... 

The Debye model is more appropriate for the acoustic branches of tire elastic modes of a hanuonic solid. For molecular solids one has in addition optical branches in the elastic wave dispersion, and the Einstein model is more appropriate to describe the contribution to U and Cj from the optical branch. The above discussion for phonons is suitable for non-metallic solids. In metals, one has, in addition, the contribution from the electronic motion to Uand Cy. This is discussed later, in section (A2.2.5.6T... 

We start from the time-dependent Sclirodinger equation for the state fiinction (wave fiinction (t)) of the reactive molecular system with Hamiltonian operator // ... 

Schinke R and Huber J R 1995 Molecular dynamics in excited electronic states—time-dependent wave packet studies Femtosecond Chemistry Proc. Berlin Conf. Femtosecond Chemistry (Berlin, March 1993) (Weinheim Verlag Chemie)... 

Braun M, Metlu H and Engel V 1998 Molecular femtosecond excitation described within the Gaussian wave packet approximation J. Chem. Phys. 108 8983-8... 

Spectroscopists observed that molecules dissolved in rigid matrices gave both short-lived and long-lived emissions which were called fluorescence and phosphorescence, respectively. In 1944, Lewis and Kasha [25] proposed that molecular phosphorescence came from a triplet state and was long-lived because of the well known spin selection rule AS = 0, i.e. interactions with a light wave or with the surroundings do not readily change the spin of the electrons. 

Vaccaro P H 1995 Resonant four-wave mixing spectroscopy a new probe for vibrationally-excited species Molecular Dynamics and Spectroscopy by Stimulated Emission Pumping (Advances in Chemistry Series) vol 7, ed H-L Dai and R W Field (Singapore World Scientific) p 1... 

Molecular spectroscopy offers a fiindamental approach to intramolecular processes [18, 94]. The spectral analysis in temis of detailed quantum mechanical models in principle provides the complete infomiation about the wave-packet dynamics on a level of detail not easily accessible by time-resolved teclmiques. 

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