Rotational Analysis of the 1–4 Band of the B 2Σ+–X 2Σ+ System of 14C16O+

ABSTRACT

High-resolution emission spectrum of the 1–4 band of the B ²Σ⁺–X ²Σ⁺ transition of ¹⁴C¹⁶O⁺ was observed for the first time by conventional emission spectroscopy. The band spectrum was excited in a water-cooled Geissler lamp filled with commercial gaseous carbon monoxide enriched in about 80% of the radiocarbon ¹⁴C. A rotational analysis has been carried out and obtained molecular constants have been merged with previously published data for the B ²Σ⁺–A ²Π_i and A ²Π_i–X ²Σ⁺ transitions. The principal equilibrium constants for the ground X ²Σ⁺ state obtained from this work are ω_e = 2121.7726(98), ω_e x _e = 13.9055(27), B _e = 1.815290(30), α_e = 1.6594(33) × 10^?2, and γ_e = ? 0.377(73) × 10^?4 cm^?1. Also, presently known experimental equilibrium molecular constants of the X ²Σ⁺ states of the CO⁺ isotopic molecules are summarized and isotopic dependence of the B _e and ω _e constants is discussed.     

Rotational Analysis of the B2Σ+-X2Σ+ Bands of 12C18O+

The emission spectrum of the B²Σ⁺-X²Σ⁺ (First Negative) system of the molecular ion ¹²C¹⁸O⁺ have been photographed at a resolution sufficient to observe the spin splitting of the lines with N > 18. Four bands, 0-1, 0-3, 1-4 and 2-5, have been rotationally analyzed and the molecular constants of the B²Σ⁺ , v = 0,1, 2 and X²Σ⁺ , v =1, 3, 4, 5 have been obtained.     

The B 2Σ+–X 2Σ+ Transition of 12C17O+: The 2‐υ″ Progression

Abstract

Three new bands of the B ²Σ⁺–X ²Σ⁺ system of ¹²C¹⁷O⁺ have been investigated using conventional spectroscopic techniques. The spectra were observed in a graphite hollow‐cathode lamp by discharging molecular oxygen (enriched in about 45% of the ¹⁷O₂ isotope) under 1.0 Torr pressure. The rotational analysis of the 2–4, 2–5, and 2–6 bands was performed with the effective Hamiltonian of Brown (Brown et al., J. Mol. Spectrosc. 1979; 74: 294–318). Molecular constants were derived from a merge calculation, including both the current wavenumbers and the spectroscopic data published by the authors previously. The principal equilibrium constants for the ground state of ¹²C¹⁷O⁺ are ω_e=2185.9658(84), ω_e x _e = 14.7674(11), B _e=1.927001(38), α_e=1.8236(22)×10^?2, γ_e=?0.331(28)×10^?4, D _e=6.041(12)×10^?6, β_e=0.100(31)×10^?7 cm^?1, and the equilibrium constants for the excited state are σ_e=45876.499(15), ω_e=1712.201(12), ω_e x _e=27.3528(39), B _e=1.754109(35), α_e=2.8706(57)×10^?2, γ_e = ?1.15(19)×10^?4, D _e=7.491(20)×10^?6, β_e=2.13(12)×10^?7, γ_e = 2.0953(97)×10^?2, and α_γe=?9.46(59)×10^?4 cm^?1, respectively. Rydberg–Klein–Rees potential energy curves were constructed for the B ²Σ⁺ and X ²Σ⁺ states of this molecule, and Franck–Condon factors were calculated for the vibrational bands of the B–X system.     

Fourier spectroscopy of the Asundi system (a′3Σ+-a3Π) of 13C16O

The Asundi system (a′³Σ⁺-a³Π) of ¹³C¹⁶O has been studied between 3500 and 12 000 cm⁻¹ by high-resolution Fourier transform spectroscopy. The 10 bands, 0-0, 0−1, 1−0, 1−1, 1−2, 2−0, 2−1, 3−0, 4−0, and 4−2, were analyzed taking into account the strong perturbations appearing in the a′³Σ⁺ (v = 0,…,4) levels. Accurate perturbation parameters were obtained for all interacting states.     

Ab initio configuration interaction study on the electronic structure of the X2Σ+, B2Σ+ and 32Σ+ states of SiO+

The energy levels and electronic structure of the X²Σ⁺, B²Σ⁺ and 3²Σ⁺ states of SiO⁺ are studied using ab initio configuration interaction (CI) calculations at and around their equilibrium internuclear distances R _e. Spectroscopic constants and the vertical excitation energy from the SiO⁺ X²Σ⁺ state are predicted for the 3²Σ⁺ state. Based on the calculated CI wavefunctions, avoided crossings of the potential energy curve for the 3²Σ⁺ state and a near-degeneracy effect in the avoided crossing region are examined. The effects of the mixing of excited configuration state functions in the total electronic wavefunctions for the 1–3 ²Σ⁺ states are investigated by analysing correlation energies in terms of the contributions from classes of excited configurations. The importance of both the near-degeneracy effect and the correlation energy effect in describing correctly the electronic structure of the 3 ²Σ⁺ state in the neighbourhood of its R _e is discussed.     

High-resolution laser excitation spectroscopy: Analysis of the B2Σ+-X2Σ+ system of CaCl

Single-mode cw dye laser excitation spectra of the (0, 0), (1, 1), and (2, 2) bands of the B²Σ⁺-X²Σ⁺ system of CaCl have been observed and assigned. Some 300 independent photo-luminescence spectra have been used in making the rotational assignment and demonstrate the power of the technique of line-by-line analysis in unraveling complex spectra. Spectroscopic constants (cm^?1) obtained from a weighted least squares fit of the data are given below. Numbers in parentheses refer to 95% confidence limits in the last digit.

     

8.

Electronic Transition Moment Variation in the C2Π–X2Σ+ System of Boron Monoxide     

K. Sunanda  M. D. Saksena 《光谱学快报》2013,46(2):373-379

The extensive band system belonging to the C²Π_r–X²Σ⁺ transition of boron monoxide (BO) molecule lying in the vacuum ultraviolet region (150–230 nm) has been recorded in emission in a hollow cathode glow. A few new bands involving high v′ levels of C state have been observed. The Franck–Condon factors and r‐centroids were computed for the C–X system. By correlating the measured intensities to theory, the (relative) variation of the C–X electronic transition moment with internuclear separation was examined.     

9.

High-precision laser and RF spectroscopy of the spin-rotation and HFS interactions in the X2Σ+ and B2Σ+ states of LaO     

《Journal of Molecular Spectroscopy》1986,119(1):166-180

The spin-rotation and hyperfine interactions in the X²Σ⁺ and B²Σ⁺ electronic states of ¹³⁹La¹⁶O have been studied using Doppler-free laser-induced fluorescence and molecular-beam laser-rf double resonance. Observations were made for several values of v and many values of N, allowing evaluation of the principal interaction strengths and their N and v dependences for both the X and B states. The results are compared with earlier results for the isoelectronic system ¹³⁷Ba¹⁹F.     

10.

Extraction of the asymptotic normalization coefficient for the first 2+ level of 16O from the analysis of α12C scattering on the basis of analytical approach     

A. N. Safronov 《Bulletin of the Russian Academy of Sciences: Physics》2008,72(11):1531-1535

The information about the nuclear vertex constant G ₁₂ for the ¹⁶O(6.917 MeV, 2⁺) ? α + ¹²C vertex and the related asymptotic normalization coefficient C ¹² of the wave function of the first excited state of the ¹⁶O nucleus with the angular momentum J = 2 and positive parity is extracted on the basis of the phase analysis data for the α¹²C scattering using the N/D equations, with allowance for the Coulomb interaction effects.     

11.

A study of the α-transfer reaction in the 16O + 16O system at near-barrier energies     

《Nuclear Physics A》1986,460(2):341-351

Excitation functions and angular distributions have been measured at energies near the Coulomb barrier for the elastic scattering of ¹⁶O from ¹⁶O and for the (¹⁶O, ¹²C) α-transfer reaction to the ground state and first excited state of ²⁰Ne. No evidence for (quasi-molecular) resonances was found in the transfer excitation functions. Exact-finite-range DWBA calculations were performed employing double-folded real and Woods-Saxon optical potentials for the distorted waves. The α-transfer reaction was found to be sensitive to the choice of the optical potential and generally better fits were obtained with the folded potentials.     

12.

The ion-molecule reaction O+ (4S) + N2(X1Σ+) → NO+ (X1Σ +, v′) + N(4S) and the predissociation of the A2Σ+ and B2Π states of N2O+     

G. CHAMBAUD  H. GRITLI  P. ROSMUS  H.-J. WERNER  P. J. KNOWLES 《Molecular physics》2013,111(21):1793-1802

The potential energy surfaces (PESs) for several electronic states involved in the reaction O⁺ (⁴S) + N₂(X¹Σ⁺) → NO⁺ (X¹Σ ⁺, v′) + N(⁴S) and the role of the ionic N₂O⁺ intermediate have been investigated by ab initio calculations. The ⁴A″ PES, which correlates with the ground state educts, has a barrier of about 1 eV, and therefore at low collision energies the reaction cannot take place adiabatically on this surface. However, the spin-orbit coupling in the entrance channel allows the system to pass into the Renner-Teller system of the X² Π electronic ground state of the N₂O⁺ intermediate. The reaction then proceeds on these surfaces up to the region in the exit channel where a similar coupling allows it to reach the product quartet asymptote. At collision energies higher than about 1 eV, the reaction proceeds mainly on the adiabatic PES of the ⁴A″ state. The A²Σ⁺ state of N₂O⁺ predissociates via a vibronic coupling with the B²Π state, and in bent structures via a spin-orbit coupling with the ⁴A″ component of the ⁴II state. The electronic structure of the B²Π state is found to be of crucial importance for the understanding of the reactive processes in low lying electronic states of N₂O⁺.     

13.

Observation and analysis of the 21Σg+ state of 7Li2     

《Journal of Molecular Spectroscopy》1986,116(2):271-285

     

14.

A theoretical study of rotational-vibrational levels of the lower two 2Σ+ states of the CaH molecule     

《Journal of Molecular Spectroscopy》1987,121(2):283-293

Computation of the rotational vibrational levels of the X²Σ⁺ and B²Σ⁺ states of the CaH molecule is carried out by using the adiabatic potential curves obtained by an ab initio SCF-CI calculation (N. Honjou, M. Takagi, M. Makita, and K. Ohno, J. Phys. Soc. Japan 50, 2095–2100 (1981)). Due to two minima in the adiabatic potential curve of the B²Σ⁺ state, an irregularity is found in the rotational-vibrational levels.     

15.

Molecule opacities of X~2Σ~+, A~2Π, and B~2Σ~+ states of CS~+          下载免费PDF全文

《中国物理 B》2019,(5)

Carbon sulfide cation(CS~+) plays a dominant role in some astrophysical atmosphere environments. In this work, the rovibrational transition lines are computed for the lowest three electronic states, in which the internally contracted multireference configuration interaction approach(MRCI) with Davison size-extensivity correction(+Q) is employed to calculate the potential curves and dipole moments, and then the vibrational energies and spectroscopic constants are extracted. The Frank–Condon factors are calculated for the bands of X~2~+Σ~+–A~2Π and X~2Σ~+–B~2Σ~+systems, and the band of X~2Σ~+–A~2Π is in good agreement with the available experimental results. Transition dipole moments and the radiative lifetimes of the low-lying three states are evaluated. The opacities of the CS~+ molecule are computed at different temperatures under the pressure of 100 atms. It is found that as temperature increases, the band systems associated with different transitions for the three states become dim because of the increased population on the vibrational states and excited electronic states at high temperature.     

16.

Simulation of the Ã2Σ+–X̃2Π absorption and emission spectra of the SiCCl radical     

Alexander O. Mitrushchenkov  Vincent Brites 《Molecular physics》2015,113(13-14):1695-1703

     

17.

The B2Σ+ state of zinc deuteride     

《Journal of Molecular Spectroscopy》1986,119(1):126-136

Conventional high-resolution photographic spectroscopy has been employed to study the B²Σ-X²Σ emission system of zinc deuteride in the region 280–370 nm. The B-X system of ZnD is reported for the first time and 17 such bands have been rotationally analyzed. Many local rotational perturbations have been found in the B state and are attributable to interactions with the A²Π state. The rotational and vibrational data for ZnH (after Stenvinkel) and ZnD are complementary and enable the RKR curve for the B state to be mapped with reasonable accuracy for almost 10 000 cm⁻¹. B-X Franck-Condon factors for ZnH and ZnD are also reported.     

18.

Accurate potential energy function and spectroscopic study of the X~2Σ~+,A~2Ⅱ and B~2Σ~+ states of the CP radical          下载免费PDF全文

刘玉芳  贾毅 《中国物理 B》2011,(3):174-180

This paper calculates the equilibrium internuclear separations,the harmonic frequencies and the potential energy curves of the X 2 Σ +,A 2Ⅱ and B 2 Σ + states of the CP radical by the highly accurate valence internally contracted multireference configuration interaction method with correlation-consistent basis sets(aug-cc-pV6Z for C atom and aug-cc-pVQZ for P atom).The potential energy curves are all fitted with the analytic potential energy function by the least-square fitting.Employing the analytic potential energy function,we determine the spectroscopic constants(B e,α e and ω e χ e) of these states.For the X 2 Σ + state,the obtained values of D e,B e,α e,ω e χ e,R e and ω e are 5.4831 eV,0.792119 cm 1,0.005521 cm 1,6.89653 cm 1,0.15683 nm,12535.11 cm 1,respectively.For the A 2Ⅱ state,the present values of D e,B e,α e,ω e χ e,R e and ω e are 4.586 eV,0.703333 cm 1,0.005458 cm 1,6.03398 cm 1,0.16613 nm,1057.89 cm 1,respectively.For the B 2 Σ + state,the present values of D e,B e,α e,ω e χ e,R e and ω e are 3.506 eV,0.677561 cm 1,0.00603298 cm 1,5.68809 cm 1,0.1696 nm,822.554 cm 1,respectively.For these states,the vibrational states with the rotational quantum number J equals zero(J = 0) are studied by solving the radial nuclear Schro¨dinger equation using the Numerov method.For each vibrational state,the vibrational level,the classical turning points,the rotational inertial and the centrifugal distortion constants are calculated.Comparison is made with recent theoretical and experimental results.     

19.

Absolute Line Intensities in the 2ν3Band of16O12C32S     

《Journal of Molecular Spectroscopy》1997,185(1):26-30

The strengths of 100 lines in the 2ν₃band of¹⁶O¹²C³²S have been measured at high resolution in the spectral range 4069–4118 cm⁻¹, using a tunable difference-frequency laser spectrometer. These intensities were obtained by fitting Voigt profiles to the measured shapes of the lines. The vibrational transition moment [(2.141 ± 0.020) × 10⁻²D] and the absolute intensity (16.19 ± 0.24 cm⁻²atm⁻¹at 296 K) of the 2ν₃band of¹⁶O¹²C³²S are determined from these linestrength measurements.     

20.

High-resolution study of the b 1Σ+-X 3Σ− emission system of 80SeO     

《Journal of Molecular Spectroscopy》1987,125(1):66-75

     

	$\text{X}{}^2\text{Σ}{}^{\mathrm{+}}$	$\text{B}{}^2\text{Σ}{}^{\mathrm{+}}$
$\text{T}{}_{\mathrm{e}}$	0	16856.69(2)
$\text{ω}{}_{\mathrm{e}}$	369.8(10)	366.8(10)
$\text{ω}{}_{\mathrm{e}}\text{x}{}_{\mathrm{e}}$	1.13(20)	1.28(20)
$\text{B}{}_{\mathrm{e}}$	0.15200(54)	0.15448(54)
$\text{α}{}_{\mathrm{e}}$	0.00063(34)	0.00073(35)
$\text{D}{}_{\mathrm{e}}$	1.027(16) × 10?7	1.097(17) × 10?7
$\text{γ}{}_{\mathrm{e}}$ (spin-rotation)	+0.003	?0.0630(16)

Electronic Transition Moment Variation in the C2Π–X2Σ+ System of Boron Monoxide

The extensive band system belonging to the C²Π_r–X²Σ⁺ transition of boron monoxide (BO) molecule lying in the vacuum ultraviolet region (150–230 nm) has been recorded in emission in a hollow cathode glow. A few new bands involving high v′ levels of C state have been observed. The Franck–Condon factors and r‐centroids were computed for the C–X system. By correlating the measured intensities to theory, the (relative) variation of the C–X electronic transition moment with internuclear separation was examined.     

High-precision laser and RF spectroscopy of the spin-rotation and HFS interactions in the X2Σ+ and B2Σ+ states of LaO

The spin-rotation and hyperfine interactions in the X²Σ⁺ and B²Σ⁺ electronic states of ¹³⁹La¹⁶O have been studied using Doppler-free laser-induced fluorescence and molecular-beam laser-rf double resonance. Observations were made for several values of v and many values of N, allowing evaluation of the principal interaction strengths and their N and v dependences for both the X and B states. The results are compared with earlier results for the isoelectronic system ¹³⁷Ba¹⁹F.     

Extraction of the asymptotic normalization coefficient for the first 2+ level of 16O from the analysis of α12C scattering on the basis of analytical approach

The information about the nuclear vertex constant G ₁₂ for the ¹⁶O(6.917 MeV, 2⁺) ? α + ¹²C vertex and the related asymptotic normalization coefficient C ¹² of the wave function of the first excited state of the ¹⁶O nucleus with the angular momentum J = 2 and positive parity is extracted on the basis of the phase analysis data for the α¹²C scattering using the N/D equations, with allowance for the Coulomb interaction effects.     

A study of the α-transfer reaction in the 16O + 16O system at near-barrier energies

Excitation functions and angular distributions have been measured at energies near the Coulomb barrier for the elastic scattering of ¹⁶O from ¹⁶O and for the (¹⁶O, ¹²C) α-transfer reaction to the ground state and first excited state of ²⁰Ne. No evidence for (quasi-molecular) resonances was found in the transfer excitation functions. Exact-finite-range DWBA calculations were performed employing double-folded real and Woods-Saxon optical potentials for the distorted waves. The α-transfer reaction was found to be sensitive to the choice of the optical potential and generally better fits were obtained with the folded potentials.     

The ion-molecule reaction O+ (4S) + N2(X1Σ+) → NO+ (X1Σ +, v′) + N(4S) and the predissociation of the A2Σ+ and B2Π states of N2O+

The potential energy surfaces (PESs) for several electronic states involved in the reaction O⁺ (⁴S) + N₂(X¹Σ⁺) → NO⁺ (X¹Σ ⁺, v′) + N(⁴S) and the role of the ionic N₂O⁺ intermediate have been investigated by ab initio calculations. The ⁴A″ PES, which correlates with the ground state educts, has a barrier of about 1 eV, and therefore at low collision energies the reaction cannot take place adiabatically on this surface. However, the spin-orbit coupling in the entrance channel allows the system to pass into the Renner-Teller system of the X² Π electronic ground state of the N₂O⁺ intermediate. The reaction then proceeds on these surfaces up to the region in the exit channel where a similar coupling allows it to reach the product quartet asymptote. At collision energies higher than about 1 eV, the reaction proceeds mainly on the adiabatic PES of the ⁴A″ state. The A²Σ⁺ state of N₂O⁺ predissociates via a vibronic coupling with the B²Π state, and in bent structures via a spin-orbit coupling with the ⁴A″ component of the ⁴II state. The electronic structure of the B²Π state is found to be of crucial importance for the understanding of the reactive processes in low lying electronic states of N₂O⁺.     

A theoretical study of rotational-vibrational levels of the lower two 2Σ+ states of the CaH molecule

Computation of the rotational vibrational levels of the X²Σ⁺ and B²Σ⁺ states of the CaH molecule is carried out by using the adiabatic potential curves obtained by an ab initio SCF-CI calculation (N. Honjou, M. Takagi, M. Makita, and K. Ohno, J. Phys. Soc. Japan 50, 2095–2100 (1981)). Due to two minima in the adiabatic potential curve of the B²Σ⁺ state, an irregularity is found in the rotational-vibrational levels.     

Molecule opacities of X~2Σ~+, A~2Π, and B~2Σ~+ states of CS~+

Carbon sulfide cation(CS~+) plays a dominant role in some astrophysical atmosphere environments. In this work, the rovibrational transition lines are computed for the lowest three electronic states, in which the internally contracted multireference configuration interaction approach(MRCI) with Davison size-extensivity correction(+Q) is employed to calculate the potential curves and dipole moments, and then the vibrational energies and spectroscopic constants are extracted. The Frank–Condon factors are calculated for the bands of X~2~+Σ~+–A~2Π and X~2Σ~+–B~2Σ~+systems, and the band of X~2Σ~+–A~2Π is in good agreement with the available experimental results. Transition dipole moments and the radiative lifetimes of the low-lying three states are evaluated. The opacities of the CS~+ molecule are computed at different temperatures under the pressure of 100 atms. It is found that as temperature increases, the band systems associated with different transitions for the three states become dim because of the increased population on the vibrational states and excited electronic states at high temperature.     

The B2Σ+ state of zinc deuteride

Conventional high-resolution photographic spectroscopy has been employed to study the B²Σ-X²Σ emission system of zinc deuteride in the region 280–370 nm. The B-X system of ZnD is reported for the first time and 17 such bands have been rotationally analyzed. Many local rotational perturbations have been found in the B state and are attributable to interactions with the A²Π state. The rotational and vibrational data for ZnH (after Stenvinkel) and ZnD are complementary and enable the RKR curve for the B state to be mapped with reasonable accuracy for almost 10 000 cm⁻¹. B-X Franck-Condon factors for ZnH and ZnD are also reported.     

Accurate potential energy function and spectroscopic study of the X~2Σ~+,A~2Ⅱ and B~2Σ~+ states of the CP radical

This paper calculates the equilibrium internuclear separations,the harmonic frequencies and the potential energy curves of the X 2 Σ +,A 2Ⅱ and B 2 Σ + states of the CP radical by the highly accurate valence internally contracted multireference configuration interaction method with correlation-consistent basis sets(aug-cc-pV6Z for C atom and aug-cc-pVQZ for P atom).The potential energy curves are all fitted with the analytic potential energy function by the least-square fitting.Employing the analytic potential energy function,we determine the spectroscopic constants(B e,α e and ω e χ e) of these states.For the X 2 Σ + state,the obtained values of D e,B e,α e,ω e χ e,R e and ω e are 5.4831 eV,0.792119 cm 1,0.005521 cm 1,6.89653 cm 1,0.15683 nm,12535.11 cm 1,respectively.For the A 2Ⅱ state,the present values of D e,B e,α e,ω e χ e,R e and ω e are 4.586 eV,0.703333 cm 1,0.005458 cm 1,6.03398 cm 1,0.16613 nm,1057.89 cm 1,respectively.For the B 2 Σ + state,the present values of D e,B e,α e,ω e χ e,R e and ω e are 3.506 eV,0.677561 cm 1,0.00603298 cm 1,5.68809 cm 1,0.1696 nm,822.554 cm 1,respectively.For these states,the vibrational states with the rotational quantum number J equals zero(J = 0) are studied by solving the radial nuclear Schro¨dinger equation using the Numerov method.For each vibrational state,the vibrational level,the classical turning points,the rotational inertial and the centrifugal distortion constants are calculated.Comparison is made with recent theoretical and experimental results.     

Absolute Line Intensities in the 2ν3Band of16O12C32S

The strengths of 100 lines in the 2ν₃band of¹⁶O¹²C³²S have been measured at high resolution in the spectral range 4069–4118 cm⁻¹, using a tunable difference-frequency laser spectrometer. These intensities were obtained by fitting Voigt profiles to the measured shapes of the lines. The vibrational transition moment [(2.141 ± 0.020) × 10⁻²D] and the absolute intensity (16.19 ± 0.24 cm⁻²atm⁻¹at 296 K) of the 2ν₃band of¹⁶O¹²C³²S are determined from these linestrength measurements.