Spectrum, rovibrational

Luckhaus D 1997 The rovibrational spectrum of hydroxylamine a combined high resolution experimental and theoretical study J. Chem. Phys. 106 8409-26... 

Rotational and Rovibrational Spectrum of C1SNC15N in the Region cf the Bending Modes v4, v5, the Combination Band v4+v5 and the Fermi Interacting Modes v3, 2v4. 

Jeziorska M, Jankowski P, Jeziorski B, Szalewicz K (2000) On the optimal choice of monomer geometry in calculations of intermolecular interaction energies, rovibrational spectrum of ar—hf from two- and three-dimensional sapt potentials. J Chem Phys 113 2957-2968... 

Fig. 5.22. Records of [OH], [H] and T from rovibrational spectrum and REMPI studies. (Reprinted with permission from reference [37], Royal Society of London.)...

Infrared spectroscopy has broad applications for sensitive molecular speciation. Infrared frequencies depend on the masses of the atoms involved in the various vibrational motions, and on the force constants and geometry of the bonds connecting them band shapes are determined by the rotational structure and hence by the molecular symmetry and moments of inertia. The rovibrational spectrum of a gas thus provides direct molecular structural information, resulting in very high specificity. The vibrational spectrum of any molecule is unique, except for those of optical isomers. Every molecule, except homonudear diatomics such as 02, N2, and the halogens, has at least one vibrational absorption in the infrared. Several texts treat infrared instrumentation and techniques (22,36—38) and their applications (39—42). 

More detailed investigations [118] included a deeper look at the SO rovibrational spectrum and a resonance enhanced multiphoton ionization (REMPI) analysis of the methyl radicals. These resulted in total rovibrational energies for the fragments. The translational energy component was not measured. The quantum yield for formation of SO in its ground electronic state ( Z) was unity within experimental error. Evidence for two types of methyl radicals, as might be expected for stepwise decomposition, was not found, so the authors suggested that the three-body dissociation pathway was dominant [118]. 

Eq. (2.112) represents an anharmonic expansion in the quantum number V. We insist, of course, on the essential difference between the one- and three-dimensional case, as in the latter case, we also obtain the rotational contribution to the energy spectrum. As a matter of fact, the final outcome of the dynamical symmetry 0(4) is the (well-approximated) rovibrational spectrum of a three-dimensional Morse oscillator. Its physical parameters can easily be related to the algebraic quantities A, N, Eg, and B by means of the following relations ... 

In this section we study in detail the Hamiltonian operator (4.23) with the aim of describing the rovibrational spectrum of an either symmetric or nonsymmetric bent triatomic molecule. Therefore, we need to complete the conversion from algebraic to rovibrational quantum numbers [Eq. (4.30)]. It is possible to show [69] that the desired relations for the bending-rotation part are given by... 

Monte Carlo with Replica Exchange (p. 375) normal modes (p. 355) rovibrational spectrum (p. 340) simulated annealing (p. 370) spatial cmelation (p. 366) thermalizatiim (p. 367) thermodynamic minimum (p. 353) time correlation (p. 366) torsional potmtial (p. 349)... 

Jacobi coordinate system (p. 279) angular momenta addition (p. 281) rovibrational spectrum (p. 283) dipole moment (p. 283) sum of states (p. 283) force field (p. 284)... 

Korobov, V.I., Leading-order relativistic and radiative corrections to the rovibrational spectrum of H2" " and HD molecular ions, Phys. Rev. A, 74,052506, 2006. 

This pattern of transitions in the rovibrational spectrum of the diatomic is roughly similar to the appearance of a rovibronic spectrum. Equations 9.27 and 9.28 need to be adjusted to include the equilibrium term energy for the difference in energy between the potential minima for the initial and final electronic states and to separate the power series expansions in the vibrational and rotational energies. Parameters such as B (o, and depend on the potential energy curve of each individual electronic state. No simple equation relates these potential energy curves for different electronic states, and therefore distinct values for each of these parameters are given to each electronic state ... 

A rovibrational spectrum is a set of transitions in which both the rotational and vibrational quantum state may change. 

Derive an equation in terms of B and for the spacing between transitions in the R and P branches of a rovibrational spectrum. 

The v = 0 1 rovibrational spectrum of potassium iodide (KI) is drawn in the following figure. 

FIGURE 14.35 Complete P and R branches of the rovibrational spectrum of HCl gas. The doublet character of each absorption is due to the natural isotopic abundances of Cl and Cl. 

Rovibrational spectra for nonlinear polyatomic molecules are more complicated. For polyatomic molecules that have a permanent dipole moment, there can be up to three independent rotational lines superimposed on a single normal vibration of the molecule. Figure 14.38 shows a rovibrational spectrum of H2O in the gas phase, where the molecules can rotate freely. Even though we have increased the size of our molecular system by only one atom, the complexity of the spectrum has increased dramatically. But because of the large amount of molecular data that can be derived from such spectra, the detailed study of the rotational-vibrational spectra of nonlinear polyatomic molecules is as rewarding as it is complex. 

Silane, SiH4, has a tetrahedral geometry and a rovibrational spectrum consisting of lines spaced by 5.92 cm . Calculate the Si-H bond distance in silane. Could this information be obtained by pure rotational spectroscopy Why or why not ... 

The rovibrational spectrum of acetylene, H—C C—H, shows intensity variations consistent with expected nuclear degeneracies. Would you expect D—C=C—H to show similar intensity variations Why or why not ... 

Chang, B., Akin-Ojo, O., Bukowski, R., 8c Szalewicz, K. (2003). Potential energy surface and rovibrational spectrum of He-N2 0 dimer. Journal of Chemical Physics, 119,11654. 

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