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Lauri Halonen - One of the best experts on this subject based on the ideXlab platform.
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calculation of the o h stretching vibrational Overtone Spectrum of the water dimer
Journal of Physical Chemistry A, 2008Co-Authors: Teemu Salmi, Henrik G Kjaergaard, Vesa Hanninen, Anna L Garden, Jonathan Tennyson, Lauri HalonenAbstract:The O−H stretching vibrational Overtone Spectrum of the water dimer has been calculated with the dimer modeled as two individually vibrating monomer units. Vibrational term values and absorption intensities have been obtained variationally with a computed dipole moment surface and an internal coordinate Hamiltonian, which consists of exact kinetic energy operators within the Born−Oppenheimer approximation of the monomer units. Three-dimensional ab initio potential energy and dipole moment surfaces have been calculated using the internal coordinates of the monomer units using the coupled cluster method including single, double, and perturbative triple excitations [CCSD(T)] with the augmented correlation consistent valence triple ζ basis set (aug-cc-pVTZ). The augmented correlation consistent valence quadruple ζ basis set (aug-cc-pVQZ), counterpoise correction, basis set extrapolation to the complete basis set limit, relativistic corrections, and core and valence electron correlations effects have been incl...
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Calculation of the O−H Stretching Vibrational Overtone Spectrum of the Water Dimer
Journal of Physical Chemistry A, 2008Co-Authors: Teemu Salmi, Henrik G Kjaergaard, Vesa Hanninen, Anna L Garden, Jonathan Tennyson, Lauri HalonenAbstract:The O−H stretching vibrational Overtone Spectrum of the water dimer has been calculated with the dimer modeled as two individually vibrating monomer units. Vibrational term values and absorption intensities have been obtained variationally with a computed dipole moment surface and an internal coordinate Hamiltonian, which consists of exact kinetic energy operators within the Born−Oppenheimer approximation of the monomer units. Three-dimensional ab initio potential energy and dipole moment surfaces have been calculated using the internal coordinates of the monomer units using the coupled cluster method including single, double, and perturbative triple excitations [CCSD(T)] with the augmented correlation consistent valence triple ζ basis set (aug-cc-pVTZ). The augmented correlation consistent valence quadruple ζ basis set (aug-cc-pVQZ), counterpoise correction, basis set extrapolation to the complete basis set limit, relativistic corrections, and core and valence electron correlations effects have been incl...
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computational resolution enhancement congested Overtone Spectrum of diacetylene
Molecular Physics, 2003Co-Authors: Markus Metsala, Olavi Vaittinen, Lauri Halonen, Shengfu Yang, Tommi Lantta, Wolfgang Jerzembeck, Matti R Hollberg, Jyrki KauppinenAbstract:The first CH stretching Overtone band system of diacetylene (1,3-butadiyne) in the range of 6350–6750 cm−1 has been recorded with a high resolution Fourier transform infrared interferometer at room temperature. Although the Spectrum obtained may be resolved rotationally, two different computational procedures have been used to enhance the resolution due to severe congestion in the central parts of the band system. It has become possible both to find one new band and to achieve higher precision. Altogether five bands with the lower state being the ground vibrational state have been analysed rotationally. The results obtained are discussed in the context of a previous molecular beam study of a small part of the same band system.
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High-Resolution Fourier Transform Infrared Spectrum of the ν1+ν3 Band System of H13C12CH
Journal of Molecular Spectroscopy, 2002Co-Authors: Tommi Lantta, Olavi Vaittinen, Markus Metsala, Lauri HalonenAbstract:Abstract A high-resolution vibration–rotation Overtone Spectrum of H 13 C 12 CH has been recorded with a Fourier transform infrared spectrometer in the wavenumber region 6400 to 6700 cm −1 . The main band, assigned as the C–H stretching combination band ν 1 +ν 3 , and some Overtone and hot bands have been rotationally analyzed. Altogether eight parallel bands have been observed. The vibrational labels have been deduced on the basis of the assignments of the fundamental ν 3 antisymmetric C–H stretching band system.
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High-resolution cavity ring-down study of acetylene between 12260 and 12380cm−1
Chemical Physics Letters, 2001Co-Authors: Markus Metsala, Olavi Vaittinen, Shengfu Yang, Dmitri Permogorov, Lauri HalonenAbstract:Abstract The cavity ring-down laser method using a continuously tunable titanium:sapphire ring laser with an external high-finesse cavity has been used to record a high-resolution Overtone Spectrum of a gaseous 12 C 2 H 2 sample in the wavenumber region 12 260–12 380 cm −1 . A direct non-linear least-squares fitting of the ring-down signal is found to lead to increased sensitivity when compared with the linear-least squares methods. Two new bands have been observed and rotationally analysed. A comparison of the new results with previous theoretical work shows a good agreement.
James P Reilly - One of the best experts on this subject based on the ideXlab platform.
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A new method for probing highly vibrationally excited molecules
Advances in Laser Science-III, 2008Co-Authors: Constantine Douketis, James P ReillyAbstract:In this paper the Δv=4 vibrational Overtone Spectrum of room temperature hydrogen peroxide vapor is reported as recorded under low (1 cm−1) and high (Doppler limited) resolution conditions. The complexity of the observed spectra motivated a study of this same transition under supersonic beam conditions. Preliminary results obtained in this study are reported.
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the 3ν1 ν3 vibrational Overtone Spectrum of 13ch4
Principles and Practice of Constraint Programming, 1995Co-Authors: Kirk Boraas, James P ReillyAbstract:Abstract The 3 ν 1 + ν 3 vibrational Overtone Spectrum of 13 CH 4 is recorded under Doppler-limited resolution conditions using a titanium sapphire laser-based photoacoustic spectrometer. Data at two temperatures, 100 and 293 K, are presented. The observed spectral congestion is qualitatively similar to that observed for 12 CH 4 , but the detailed ro-vibrational structure of the two isotope variants is completely different. The data reflect the complicating influences of tetrahedral fine structure and vibrational state mixing.
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The 3ν1 + ν3 vibrational Overtone Spectrum of 13CH4
1995Co-Authors: Kirk Boraas, James P ReillyAbstract:Abstract The 3 ν 1 + ν 3 vibrational Overtone Spectrum of 13 CH 4 is recorded under Doppler-limited resolution conditions using a titanium sapphire laser-based photoacoustic spectrometer. Data at two temperatures, 100 and 293 K, are presented. The observed spectral congestion is qualitatively similar to that observed for 12 CH 4 , but the detailed ro-vibrational structure of the two isotope variants is completely different. The data reflect the complicating influences of tetrahedral fine structure and vibrational state mixing.
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the vibrational Overtone Spectrum of fluoroform in the δν 4 ch stretching region
Chemical Physics Letters, 1994Co-Authors: Kirk Boraas, James P ReillyAbstract:Abstract The vibrational Overtone Spectrum of fluoroform in the Δν=4 CH stretching region was recorded by intracavity photoacoustic spectroscopy at room temperature and at 166 K with a resolution limited by Doppler broadening. Of the three bands observed, only one shows clearly resolved J rotational structure.
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The vibrational Overtone Spectrum of fluoroform in the Δν=4 CH stretching region
Chemical Physics Letters, 1994Co-Authors: Kirk Boraas, James P ReillyAbstract:Abstract The vibrational Overtone Spectrum of fluoroform in the Δν=4 CH stretching region was recorded by intracavity photoacoustic spectroscopy at room temperature and at 166 K with a resolution limited by Doppler broadening. Of the three bands observed, only one shows clearly resolved J rotational structure.
Kirk Boraas - One of the best experts on this subject based on the ideXlab platform.
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the 3ν1 ν3 vibrational Overtone Spectrum of 13ch4
Principles and Practice of Constraint Programming, 1995Co-Authors: Kirk Boraas, James P ReillyAbstract:Abstract The 3 ν 1 + ν 3 vibrational Overtone Spectrum of 13 CH 4 is recorded under Doppler-limited resolution conditions using a titanium sapphire laser-based photoacoustic spectrometer. Data at two temperatures, 100 and 293 K, are presented. The observed spectral congestion is qualitatively similar to that observed for 12 CH 4 , but the detailed ro-vibrational structure of the two isotope variants is completely different. The data reflect the complicating influences of tetrahedral fine structure and vibrational state mixing.
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The 3ν1 + ν3 vibrational Overtone Spectrum of 13CH4
1995Co-Authors: Kirk Boraas, James P ReillyAbstract:Abstract The 3 ν 1 + ν 3 vibrational Overtone Spectrum of 13 CH 4 is recorded under Doppler-limited resolution conditions using a titanium sapphire laser-based photoacoustic spectrometer. Data at two temperatures, 100 and 293 K, are presented. The observed spectral congestion is qualitatively similar to that observed for 12 CH 4 , but the detailed ro-vibrational structure of the two isotope variants is completely different. The data reflect the complicating influences of tetrahedral fine structure and vibrational state mixing.
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the vibrational Overtone Spectrum of fluoroform in the δν 4 ch stretching region
Chemical Physics Letters, 1994Co-Authors: Kirk Boraas, James P ReillyAbstract:Abstract The vibrational Overtone Spectrum of fluoroform in the Δν=4 CH stretching region was recorded by intracavity photoacoustic spectroscopy at room temperature and at 166 K with a resolution limited by Doppler broadening. Of the three bands observed, only one shows clearly resolved J rotational structure.
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The vibrational Overtone Spectrum of fluoroform in the Δν=4 CH stretching region
Chemical Physics Letters, 1994Co-Authors: Kirk Boraas, James P ReillyAbstract:Abstract The vibrational Overtone Spectrum of fluoroform in the Δν=4 CH stretching region was recorded by intracavity photoacoustic spectroscopy at room temperature and at 166 K with a resolution limited by Doppler broadening. Of the three bands observed, only one shows clearly resolved J rotational structure.
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the vibrational Overtone Spectrum of propyne in the acetylenic ch δv 4 region
Journal of Molecular Spectroscopy, 1992Co-Authors: Kirk Boraas, James P ReillyAbstract:Abstract The vibrational Overtone Spectrum of propyne (CH 3 CCH) in the acetylenic CH Δ v = 4 region was obtained by intracavity photoacoustic spectroscopy with a resolution limited by room-temperature Doppler broadening and pressure broadening. By comparison with a symmetric-top simulation, the observed Spectrum was assigned as a rotationally resolved parallel band overlapped by a hot band.
Olavi Vaittinen - One of the best experts on this subject based on the ideXlab platform.
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computational resolution enhancement congested Overtone Spectrum of diacetylene
Molecular Physics, 2003Co-Authors: Markus Metsala, Olavi Vaittinen, Lauri Halonen, Shengfu Yang, Tommi Lantta, Wolfgang Jerzembeck, Matti R Hollberg, Jyrki KauppinenAbstract:The first CH stretching Overtone band system of diacetylene (1,3-butadiyne) in the range of 6350–6750 cm−1 has been recorded with a high resolution Fourier transform infrared interferometer at room temperature. Although the Spectrum obtained may be resolved rotationally, two different computational procedures have been used to enhance the resolution due to severe congestion in the central parts of the band system. It has become possible both to find one new band and to achieve higher precision. Altogether five bands with the lower state being the ground vibrational state have been analysed rotationally. The results obtained are discussed in the context of a previous molecular beam study of a small part of the same band system.
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High-Resolution Fourier Transform Infrared Spectrum of the ν1+ν3 Band System of H13C12CH
Journal of Molecular Spectroscopy, 2002Co-Authors: Tommi Lantta, Olavi Vaittinen, Markus Metsala, Lauri HalonenAbstract:Abstract A high-resolution vibration–rotation Overtone Spectrum of H 13 C 12 CH has been recorded with a Fourier transform infrared spectrometer in the wavenumber region 6400 to 6700 cm −1 . The main band, assigned as the C–H stretching combination band ν 1 +ν 3 , and some Overtone and hot bands have been rotationally analyzed. Altogether eight parallel bands have been observed. The vibrational labels have been deduced on the basis of the assignments of the fundamental ν 3 antisymmetric C–H stretching band system.
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High-resolution cavity ring-down study of acetylene between 12260 and 12380cm−1
Chemical Physics Letters, 2001Co-Authors: Markus Metsala, Olavi Vaittinen, Shengfu Yang, Dmitri Permogorov, Lauri HalonenAbstract:Abstract The cavity ring-down laser method using a continuously tunable titanium:sapphire ring laser with an external high-finesse cavity has been used to record a high-resolution Overtone Spectrum of a gaseous 12 C 2 H 2 sample in the wavenumber region 12 260–12 380 cm −1 . A direct non-linear least-squares fitting of the ring-down signal is found to lead to increased sensitivity when compared with the linear-least squares methods. Two new bands have been observed and rotationally analysed. A comparison of the new results with previous theoretical work shows a good agreement.
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high resolution photoacoustic Overtone Spectrum of monobromoacetylene hccbr above 11 600 cm 1
Journal of Molecular Spectroscopy, 1998Co-Authors: Olavi Vaittinen, P Jungner, Lauri Halonen, Markku Hamalainen, Kirsi Pulkkinen, Hans Burger, O PolanzAbstract:Photoacoustic Overtone spectra of monobromoacetylene, HCCBr, have been recorded in the wavenumber region 11600–13400 cm−1using a titanium:sapphire ring laser spectrometer. All together, eight Overtone bands of HCC79Br and eight bands of HCC81Br have been observed in the rotational analysis. A Fermi resonance model based on conventional normal coordinate theory has been used to vibrationally assign the rotationally analyzed bands. The resonance model employed reproduces well the observed vibrational band origins and rotational constants.
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High-Resolution Photoacoustic Overtone Spectrum of Monobromoacetylene, HCCBr, above 11 600 cm−1
Journal of Molecular Spectroscopy, 1998Co-Authors: Olavi Vaittinen, P Jungner, Lauri Halonen, Markku Hamalainen, Kirsi Pulkkinen, Hans Burger, O PolanzAbstract:Photoacoustic Overtone spectra of monobromoacetylene, HCCBr, have been recorded in the wavenumber region 11600–13400 cm−1using a titanium:sapphire ring laser spectrometer. All together, eight Overtone bands of HCC79Br and eight bands of HCC81Br have been observed in the rotational analysis. A Fermi resonance model based on conventional normal coordinate theory has been used to vibrationally assign the rotationally analyzed bands. The resonance model employed reproduces well the observed vibrational band origins and rotational constants.
Henrik G Kjaergaard - One of the best experts on this subject based on the ideXlab platform.
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Calculation of the O−H Stretching Vibrational Overtone Spectrum of the Water Dimer
Journal of Physical Chemistry A, 2008Co-Authors: Teemu Salmi, Henrik G Kjaergaard, Vesa Hanninen, Anna L Garden, Jonathan Tennyson, Lauri HalonenAbstract:The O−H stretching vibrational Overtone Spectrum of the water dimer has been calculated with the dimer modeled as two individually vibrating monomer units. Vibrational term values and absorption intensities have been obtained variationally with a computed dipole moment surface and an internal coordinate Hamiltonian, which consists of exact kinetic energy operators within the Born−Oppenheimer approximation of the monomer units. Three-dimensional ab initio potential energy and dipole moment surfaces have been calculated using the internal coordinates of the monomer units using the coupled cluster method including single, double, and perturbative triple excitations [CCSD(T)] with the augmented correlation consistent valence triple ζ basis set (aug-cc-pVTZ). The augmented correlation consistent valence quadruple ζ basis set (aug-cc-pVQZ), counterpoise correction, basis set extrapolation to the complete basis set limit, relativistic corrections, and core and valence electron correlations effects have been incl...
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calculation of the o h stretching vibrational Overtone Spectrum of the water dimer
Journal of Physical Chemistry A, 2008Co-Authors: Teemu Salmi, Henrik G Kjaergaard, Vesa Hanninen, Anna L Garden, Jonathan Tennyson, Lauri HalonenAbstract:The O−H stretching vibrational Overtone Spectrum of the water dimer has been calculated with the dimer modeled as two individually vibrating monomer units. Vibrational term values and absorption intensities have been obtained variationally with a computed dipole moment surface and an internal coordinate Hamiltonian, which consists of exact kinetic energy operators within the Born−Oppenheimer approximation of the monomer units. Three-dimensional ab initio potential energy and dipole moment surfaces have been calculated using the internal coordinates of the monomer units using the coupled cluster method including single, double, and perturbative triple excitations [CCSD(T)] with the augmented correlation consistent valence triple ζ basis set (aug-cc-pVTZ). The augmented correlation consistent valence quadruple ζ basis set (aug-cc-pVQZ), counterpoise correction, basis set extrapolation to the complete basis set limit, relativistic corrections, and core and valence electron correlations effects have been incl...
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the oh stretching and ooh bending Overtone Spectrum of hoono
Journal of Chemical Physics, 2005Co-Authors: Daniel P Schofield, Henrik G Kjaergaard, Jamie Matthews, Amitabha SinhaAbstract:We have simulated the HOONO vibrational Overtone Spectrum with use of a local mode Hamiltonian that includes the OH-stretching, OOH-bending, and NOOH-torsional modes and coupling between all three modes. The local mode parameters and the dipole moment function are calculated with coupled-cluster ab initio theory and an augmented Dunning-type triple-zeta basis set. We investigate the accuracy of the local mode parameters obtained from two different potential-energy fitting routines, as well as the sensitivity of these parameters to the basis set employed. We compare our simulated spectra to previously published action spectra in the first and second OH-stretching Overtone regions. In addition we have recorded the Spectrum in the OH-stretch and OOH-bend combination region around 7700cm−1 and we also compare to this. Our simulated Spectrum is in qualitative agreement with experiment in the first and second OH-stretching Overtone and in the stretch-bend regions.
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resonance coupling in the fourth oh stretching Overtone Spectrum of formic acid
Journal of Chemical Physics, 2004Co-Authors: Daryl L Howard, Henrik G KjaergaardAbstract:The room-temperature vibrational Overtone spectra of the formic acid isotopomers HCOOH and DCOOH have been recorded in the third and fourth OH-stretching Overtone regions with intracavity laser photoacoustic spectroscopy. Resonance coupling between the OH- and CH-stretching vibrations in HCOOH is clearly identified in the fourth Overtone region. This is an example of strong coupling across bonds. In the third Overtone region, no resonance is observed. Vibrational energies and intensities of the OH- and CH-stretching Overtones and combination bands have been calculated with an anharmonic oscillator local mode model. The pure OH-stretching bright state carries almost all the intensity prior to resonance coupling.
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deuterium isotope effects on the ch stretching Overtone Spectrum of toluene α d1
Journal of Physical Chemistry A, 1998Co-Authors: Henrik G Kjaergaard, Bryan R HenryAbstract:The room-temperature vapor phase Overtone Spectrum of toluene-α-d1 has been recorded in the CH stretching regions corresponding to ΔvCH = 2−7. The vibrational Overtone spectra are recorded by conventional near-infrared spectroscopy and by intracavity titanium:sapphire and dye laser photoacoustic spectroscopy. Absolute oscillator strengths are obtained from the conventional spectra, and relative oscillator strengths within a given Overtone, from both the conventional and photoacoustic spectra. The aryl region of the Spectrum is nearly identical to the aryl region of the Spectrum of toluene-d0 and can be understood on the basis of two nonequivalent aryl local modes. The methyl band differs markedly from the methyl band in toluene-d0 in relative intensity, in line width, and in structure. We use an anharmonic oscillator local mode model and an ab initio dipole moment function to calculate oscillator strengths for the aryl and methyl transitions. As was the case for toluene-d0, these simple calculations show ...
