Ab initio potential energy surface, electric-dipole moment, polarizability tensor, and theoretical rovibrational spectra in the electronic ground state of

Yurchenko, Sergei N.; Thiel, Walter; Carvajal, M.; Jensen, Per

doi:10.1016/j.chemphys.2008.01.052

Cited by 14 publications

(19 citation statements)

References 53 publications

(120 reference statements)

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“…The phosphine molecule was then a good candidate for the global approach successfully developed for spherical tops [10,11] and extensively applied to other complex band systems encountered in polyatomic molecules [12,13,14]. The vibrational spectrum of PH 3 and its isotopomers has also been investigated by ab initio calculations [15,16,17,18]. Recent works have reported ab initio vibrational energies [19,20] and theoretical transition moments [21].…”

Section: Introductionmentioning

confidence: 99%

Global modeling of the lower three polyads of PH3: Preliminary results

Nikitin

Champion

Butler

et al. 2009

Journal of Molecular Spectroscopy

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In order to model the high-resolution infrared spectrum of the phosphine molecule in the 3 µm region, a global approach involving the lower three polyads of the molecule (Dyad, Pentad and Octad) as been applied using an eective hamiltonian in the form of irreducible tensors. This model allowed to describe all the 15 vibrational states involved and to consider explicitly all relevant ro-vibrational interactions that cannot be accounted for by conventional perturbation approaches.2245 levels (up to J = 14) observed through transitions arising from 34 cold and hot bands including all available existing data as well as new experimental data have been tted simultaneously using a unique set of eective hamiltonian parameters.The rms achieved is 0.63 × 10 µm by dividing the rms reported by previous works by a factor 6. A preliminary intensity analysis based on consistent sets of eective dipole moment operators for cold and hot bands has been simultaneously undertaken for direct comparison between observed and modeled absorption from 700 to 3500 cm −1 .Keywords : Phosphine ; PH 3 ; Vibrational polyads ; Global modeling ; Near infrared ; High-resolution ; Positions ; Intensities IntroductionAs part of extensive eorts to support remote sensing of Jupiter and Saturn many works have been devoted to the high-resolution infrared spectrum of phosphine [1,2,3, 4, 5, 6, 7]. Recent works focused on the 3 µm region reported experimental measurements and assignments [5, 7], but so far no comprehensive modeling was reported.1 hal-00355701, version 1 -23 Jan 2009 At present, the line parameters of phosphine (positions and intensities) in the 3 µm region rely essentially on the empirical database reported in Ref. [7] and included in HITRAN [8] and GEISA [9]. In the spectral region from 2700 to 3500 cm −1 , the HITRAN compilation contains over 3000 unassigned PH 3 lines with intensities ranging from 1. × 10 −25 to 1.5 × 10 −22 cm×molecule −1 . Moreover, only one hot band arising from the upper state of ν 2 is included. The main reason for this lack of modeling is the fundamental limitation of conventional perturbation approaches. So far, only weakly interacting features could be tted using isolated band models while strongly interacting states were left out. In fact, apart from degeneracy considerations, due to the quasi spherical character of the inertia tensor of the molecule and to specic quasi coincidences among its vibrational fundamental frequencies, the vibrational pattern of the phosphine molecule is quite similar to that of the methane molecule. The phosphine molecule was then a good candidate for the global approach successfully developed for spherical tops [10,11] and extensively applied to other complex band systems encountered in polyatomic molecules [12,13,14]. The vibrational spectrum of PH 3 and its isotopomers has also been investigated by ab initio calculations [15,16,17,18]. Recent works have reported ab initio vibrational energies [19,20] and theoretical transition moments [21]. The experimental data involv...

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Section: Introductionmentioning

confidence: 99%

Global modeling of the lower three polyads of PH3: Preliminary results

Nikitin

Champion

Butler

et al. 2009

Journal of Molecular Spectroscopy

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“…are reported in Table 1. They have been computed at two levels of computation in order to allow for comparison with both our previous FC computations [10] and with some of the high-level computations published up to now [34,35]. The fourth order of the Møller Plesset perturbation theory, including single, double and quadruple excitations, in conjunction with the 6-311?…”

Section: Theoretical Approachmentioning

confidence: 99%

“…The coefficients of the fitted polynomials are given in Table 3. It must be remarked that, in the case of MP4/TZ computations, we have deliberately chosen to use a small grid of points, much smaller than those used previously in the literature [10,34,35], in order to test the effectiveness of a good choice of internal curvilinear coordinates in relieving the computational efforts of computing anharmonic potential energy hypersurfaces for the calculation of FC factors. On the contrary, CC/QZ potential energy hypersurface has been calculated over a grid of 1,653 points, covering the range 0:9Å r 1:2Å and 88.6°B h B 120.0°.…”

Section: Theoretical Approachmentioning

confidence: 99%

Franck–Condon factors in curvilinear coordinates: the photoelectron spectrum of ammonia

et al. 2012

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An approach to the calculation of FranckCondon factors in curvilinear coordinates is outlined. The approach is based on curvilinear normal coordinates, which allows for an easy extension of Duschinsky's transformation to the case of curvilinear coordinates, and on the power series expansion of the kinetic energy operator. Its usefulness in the case of molecules undergoing large displacements of their equilibrium nuclear configurations upon excitation is then demonstrated by an application to the vibrational structure of the photoelectron spectrum of ammonia, using an anharmonic potential only for the symmetric stretching and bending coordinates of the radical cation.

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“…We have applied the XY3 and TROVE programs to a series of XH 3 molecules (X = N, P, As, Sb, Bi) [1,2,5,6,7,10,12,13,14,15,16,17]. Also, TROVE has been used to predict and interpret the complicated torsional splittings of the HSOH molecule [18], to explain an intensity anomaly observed in this molecule [19,20] and to predict highly excited rotational energies in deuterated isotopologues of BiH 3 , SbH 3 , and AsH 3 [21].…”

Section: Introductionmentioning

confidence: 99%

“…Our initial work was concerned with XY 3 ammonia-type molecules and led to the XY3 theoretical model and computer program for calculating the rotation-vibration energies [1,2,3], and simulating the rotation-vibration spectra [4,5,6,7] for such molecules. The XY3 approach is entirely variational in that the rotation-vibration energies and wavefunctions are obtained by diagonalization of a matrix representation of the rotation-vibration Hamiltonian, constructed in a suitable basis set.…”

Section: Introductionmentioning

confidence: 99%