Potential energy surface study of [H, Si, C, N] and its ions

Wang, Qiang; Ye, Ding; Sun, Chenglin

doi:10.1016/j.chemphys.2005.09.043

Cited by 10 publications

(9 citation statements)

References 12 publications

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“…1͒ is based on the relative energy ordering evaluated at different levels of theory in earlier studies of both molecular systems. 9,[15][16][17] For the sake of completeness, relative energies have also been computed here using absolute energies evaluated at the CCSD͑T͒/cc-pwCVQZ level of theory and zero-point vibrational energies at the CCSD͑T͒ / cc-pV͑T + d͒Z level of theory ͑Table IX͒. To avoid resonance denominators in the anharmonicity constants used to calculate the zero-point vibrational energy ͑ZPVE͒ contribution, the socalled G 0 term was included ͑see Refs.…”

Section: E Relative Energiesmentioning

confidence: 99%

“…In case of the isoelectronic CNHSi family, Maier et al 9 found the bent chain HSiCN ͑7͒ to be the global minimum on the PES followed by the chain molecule HSiNC ͑8͒ and cyclic azasilacyclopropenylidene ͑9͒, a result confirmed by more recent theoretical studies. 16,17 The present paper reports results of high-level ab initio calculations of selected molecular properties of singlet C 2 H 2 Si and CNHSi structural isomers. In detail the study comprises the determination of molecular equilibrium structures obtained at the CCSD͑T͒ level of theory 18 using Dunning's hierarchy of correlation consistent basis sets [19][20][21][22] and evaluation of harmonic and anharmonic force fields at selected levels of theory to determine centrifugal distortion constants, vibration-rotation interaction constants, and harmonic as well as fundamental vibrational frequencies.…”

Section: Introductionmentioning

confidence: 99%

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Coupled-cluster calculations of C2H2Si and CNHSi structural isomers

Thorwirth

Harding

2009

The Journal of Chemical Physics

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Results of large-scale coupled-cluster calculations of selected C(2)H(2)Si and CNHSi structural isomers are reported. Equilibrium molecular structures of a total of 12 molecules in their singlet electronic states have been calculated systematically employing the coupled-cluster singles and doubles model augmented by a perturbative correction for triple excitations (CCSD(T)) in combination with Dunning's hierarchy of correlation consistent basis sets. In addition, anharmonic force fields were calculated to yield fundamental vibrational frequencies and rotation-vibration interaction constants alpha(i) (A,B,C). The latter were used to determine empirical equilibrium structures r(e) (emp) of two molecules - silacyclopropenylidene, c-C(2)H(2)Si, and silapropadienylidene, H(2)CCSi - for which sufficient isotopic data are available from literature. Very good agreement with theoretical equilibrium structures from CCSD(T) calculations employing core-valence basis sets of quadruple and quintuple-zeta quality - i.e., cc-pwCVQZ (337 basis functions), cc-pCV5Z, and cc-pwCV5Z (581 basis functions) is found - to within 0.001 A for bond lengths and 0.1 degrees for bond angles. Theoretical ground state rotational constants of HSiCN and HSiNC compare very favorably with experimental microwave data from literature, to within 0.15% (HSiCN) and 0.1% (HSiNC) for the B(0) and C(0) rotational constants. In the case of c-C(2)H(2)Si and H(2)CCSi this agreement is even better than 0.1%. For the latter two molecules effects of higher-level electron-correlation and relativity to the equilibrium geometry as well as the electronic contributions to the rotational constants are investigated. For eight molecules not yet studied at high spectral resolution in the gas-phase theoretical molecular parameters are provided to support future laboratory investigations. Theoretical vibrational fundamentals compare well with data of eight species studied previously with infrared matrix isolation spectroscopy.

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Section: E Relative Energiesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Coupled-cluster calculations of C2H2Si and CNHSi structural isomers

Thorwirth

Harding

2009

The Journal of Chemical Physics

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“…In the more recent theoretical study by Wang et al the potential energy surfaces of the neutral, cationic, and anionic isomers of the [H, Si, C, N] system were determined at the B3LYP/6-311(d) level of theory . Like the work by Flores et al, they found that the lowest two isomers were HSiCN and HSiNC, with HSiCN being 10.0 kJ mol −1 more stable than HSiNC.…”

Section: Introductionmentioning

confidence: 99%

Spectroscopic Investigation of the Electronic Ã¹A′′−X̃¹A′ Transition of HSiNC

Evans

Dover

2009

J. Phys. Chem. A

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The first spectroscopic investigation of the A1A''-X1A' transition of HSiNC has been reported. The 0(0)(0) band of the A1A''-X1A' transition has been rotational resolved using laser-induced fluorescence spectroscopy, and ground- and excited-state rotational and centrifugal distortion constants were evaluated. Ten additional vibrational bands belonging to HSiNC have also been observed in the laser-induced fluorescence spectrum and have been assigned based on predicted anharmonic vibrational frequencies. Because of the large change in geometry upon excitation, a number of axis-rotation peaks have been observed in the 0(0)(0) band, and the axis-rotation angle (thetaT) has been estimated to be 1.0 +/- 0.2 degrees. Dispersed fluorescence spectroscopy has also been carried out, and a number of overtones of the nu3 fundamental (Si-H wagging mode) have been observed in the ground state, and its anharmonic parameter (x(e)) was evaluated.

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“… 3 Alternatively, theoretical results or/and experimental characterization have been reported for HSiCN/HSiNC, HGeCN/HGeNC, HZnCN/HZnNC, HFeCN/HFeNC and HTiCN/HTiNC systems in order to aid for their potential astrophysical detection. 4 …”

Section: Introductionmentioning

confidence: 99%