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.

     

6.

The optical double resonance spectrum of the B̃1A1 state of Cl2CS     

《Journal of Molecular Spectroscopy》1986,115(1):74-81

     

7.

Extended analysis of the Ar VII spectrum in the vacuum ultraviolet region     

F. O.?BorgesEmail author  F.?Bredice  G. H.?Cavalcanti  M.?Gallardo  M.?Raineri  J. G.?Reyna Almandos  A. G.?Trigueiros 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2005,36(1):23-27

The current status of the determination of corrections to the hyperfine splitting of the ground state in hydrogen is considered. Improved calculations are provided taking into account the most recent value for the proton charge radius. Comparing experimental data with predictions for the hyperfine splitting, the Zemach radius of the proton is deduced to be 1.045(16) fm. Employing exponential parametrizations for the electromagnetic form factors we determine the magnetic radius of the proton to be 0.778(29) fm. Both values are compared with the corresponding ones derived from the data obtained in electron-proton scattering experiments and the data extracted from a rescaled difference between the hyperfine splittings in hydrogen and muonium.     

8.

The high-resolution spectrum of the ν1 + ν2 band of NO2: A spin-induced perturbation in the ground state     

《Journal of Molecular Spectroscopy》1987,125(1):99-114

The spectrum of the ν₁ + ν₂ band of NO₂ has been studied with a resolution of 0.025 cm⁻¹. Spin-rotation constants and rotational constants are reported. An interesting perturbation has been found in the ground state of the molecule which occurs when the K_a = 0 and K_a = 2 levels become accidentally nearly degenerate around N = 42. An explanation of this interaction is presented.     

9.

The laser-induced fluorescence study of AΣ-XΠ_i band system of CuS     

Shaohua Zhang 《Journal of Molecular Spectroscopy》2008,252(1):77-80

The laser-induced fluorescence excitation spectra of jet-cooled CuS molecules have been recorded in the energy range of 17 200-19 500 cm⁻¹. Fourteen observed vibronic bands have been assigned as three transition progressions: A²Σ⁻ (v′ = 0-4)-X²Π_3/2 (v″ = 0), A²Σ⁻ (v′ = 0-4)-X²Π_3/2 (v″ = 1), and A²Σ⁻ (v′ = 0-3)-X²Π_1/2 (v″ = 0). Spectroscopic constants of both the X²Π ground state and the A²Σ⁻ excited state of ⁶³CuS and ⁶⁵CuS were determined by analyzing their rotationally resolved spectra. Furthermore, the lifetimes of most observed bands were measured for the first time.     

10.

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

A. Antic-Jovanovic    B. R. Vujisic  V. D. Bojovic  D. S. Pesic 《光谱学快报》2013,46(8):1783-1791

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.     

11.

The high-resolution spectrum of the ν1 (A1) band of 12CD3F     

《Journal of Molecular Spectroscopy》1987,125(2):332-347

The spectrum of the ν₁ (A₁) band of ¹²CD₃F has been recorded with a resolution of 0.010 cm⁻¹ and deconvolved to 0.005 cm⁻¹. Over 1050 transitions have been assigned with K ≤ 16 and J ≤ 42. The spectrum is highly perturbed, exhibiting avoided crossings in most of the observed sub-bands. The origin of most of the local and global resonances has been determined and the coupling constants estimated. Due to the complexity of the spectrum resulting from the 24 potential interacting states in the region, the assigned frequencies were fitted in a restricted manner (K ≤ 3, J ≤ 15), to obtain the following effective constants for the band: ν₀ = 2090.8118(20) cm⁻¹, α^A = 1.19743 × 10⁻² cm⁻¹, and α^B = −1.8489 × 10⁻³ cm⁻¹. From an unrestricted least-squares analysis, fixing the above parameters the β's (D_v^x = D₀^x − β_v^x) were calculated to be β^J = 1.7776 × 10⁻⁷ cm⁻¹, β^JK = 8.3406 × 10⁻⁷ cm⁻¹, and β^K = −6.3829 × 10⁻⁷ cm⁻¹. These constants serve as good starting parameters for the global analysis necessary to fully analyze the 5-μm region of the ¹²CD₃F spectrum.     

12.

An intermodulated fluorescence study of the A2Σ−-X2Πi band system of copper monoxide     

《Journal of Molecular Spectroscopy》1986,118(1):237-247

Several lines in the A²Σ⁻(v = 0)-X²Π_i(v = 0) visible band system of gas phase copper monoxide have been measured at sub-Doppler resolution using the technique of intermodulated fluorescence. The copper nuclear magnetic hyperfine splitting is clearly resolved. The observations were fitted to an effective Hamiltonian model and values of the magnetic hyperfine parameters of b_F = −0.0302 cm⁻¹ for the A state and d = 0.0024 cm⁻¹ for the X state were determined. An interpretation of these values in terms of the proposed electronic configurations of these states is presented.     

13.

Excited vibrational levels of the ground state of B2: The A3Σu−-X3Σg− transition     

《Journal of Molecular Spectroscopy》1987,121(1):128-134

     

14.

The A1Π-X1Σ band system of CD+: Spectroscopic constants and isotope shifts     

A. Antić-Jovanović  V. Bojović  D.S. Pešić  S. Weniger 《Journal of Molecular Spectroscopy》1979,75(2):197-204

Six bands of the A¹Π-X¹Σ system of CD⁺ in the region 3800–4800 Å have been recorded in emission using an aluminum hollow-cathode discharge in the HeC₂H₂ mixture. From the vibrational and rotational analysis of the observed bands, the following constants (cm^?1) are obtained:

	$\text{X}{}^2\text{Σ}{}^{\mathrm{+}}$	$\text{B}{}^2\text{Σ}{}^{\mathrm{+}}$
$\text{T}{}_{\mathrm{e}}$	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)

     

15.

The A3Π-X0+, 1 band system of the SeO molecule     

K.K. Verma  M. Azam  S.Paddi Reddy 《Journal of Molecular Spectroscopy》1977,65(2):289-294

A new weak emission band system of the SeO molecule consisting of 34 band heads degraded to shorter wavelengths has been observed for the first time in the spectral region 6730–8570 Å. The vibrational analysis of the system suggests that it arises from the transition A³Π_reg-X0⁺, 1. All the five subsystems allowed by the selection rule $\text{ΔΩ}\text{= 0}$, ±1 have been identified. The constants in cm^?1 derived for the A³Π state are

		$\text{T}{}_{00}$		$\text{ω}{}_{\mathrm{e}}$		$\text{ω}{}_{\mathrm{e}}\text{x}{}_{\mathrm{e}}$		$\text{ω}{}_{\mathrm{e}}\text{y}{}_{\mathrm{e}}$		$\text{B}{}_{\mathrm{e}}$		$\text{D}{}_{\mathrm{e}}\text{·10}{}^4$		$\text{α}{}_{\mathrm{e}}$
$\text{A}{}^1\text{Π}$		23 747.5		1367.3		60.6		0.75		6.428		5.7		0.388
$\text{X}{}^1\text{Σ}$		0		2035						7.650		4.1		0.190
				(2101.6)		(33.3)

     

16.

Doppler-limited dye laser excitation spectroscopy of the 401 band of the Ã1A2-X̃1A1 system of D2CS     

《Journal of Molecular Spectroscopy》1987,126(1):29-31

     

17.

The Ã-X̃ band system of acetylene: Bands of the short-wavelength region     

《Journal of Molecular Spectroscopy》1986,119(1):137-143

     

18.

Rotational analysis of the a3Π-X1Σ+ bands of GaD     

《Journal of Molecular Spectroscopy》1987,122(2):417-427

A new method of producing strong and clean emission spectra of the gallium hydride/deuteride molecule has been developed. Five bands belonging to the gallium deuteride molecule (GaD) have been photographed under high resolution. The rotational analyses of the bands lying at 5669.14 Å (0-0) and 5675.10 Å (1-1) in the a³Π₁-X¹Σ⁺ transition, 5761.0 Å (0-0) and 5766.20 Å (1-1) in the a³Π_0⁺-X¹Σ⁺ transition, and 5760.85 Å (0-0) in the a³Π_0⁻-X¹Σ⁺ transition have been performed. Accurate rotational constants (B, D) have been determined for the X¹Σ⁺, a³Π_0^± and a³Π_1^± states. The Λ doubling in the a³Π₀ (v = 0) and a³Π₁ (v = 0 and 1) states are obtained.     

19.

A quasiclassical study of collisions of He with HD(B 1Σ+ u )     

Stavros C. Farantos 《Molecular physics》2013,111(4):835-845

A quasiclassical trajectory study has been carried out for collisions of ⁴He with electronically excited H₂(B ¹Σ⁺ _u ) and its isotopomer HD. By using analytical fits for the ab initio potential energy surfaces of the ground and the excited state we have obtained vibrational and electronic quenching cross sections for several initial conditions. We draw the following conclusions. Vibrational excitation strongly promotes electronic quenching whereas translational energy is less effective. Rotational excitation decreases the rate of quenching. In a remarkable contrast to the ground electronic state, vibrational energy transfer on the excited potential energy surface is an efficient and fast process. Collisions at high energies results in T → R energy transfer. The above conclusions are valid for both H₂ and HD.     

20.

Analysis of the bands of the B2Σ+-X2Σ+ transition in 12C16O+ and 13C16O+     

《Journal of Molecular Spectroscopy》1987,125(1):54-65

The First Negative bands of ¹²C¹⁶O⁺ and ¹³C¹⁶O⁺, in the spectral region 40 000–46 000 cm⁻¹, have been photographed at a resolution sufficient to resolve the spin-doubled components. These data for ¹²C¹⁶O⁺, along with previously reported data of the same transitions, as well as microwave transitions of ¹²C¹⁶O⁺ in the ground state, have been explicitly included in a least-squares fit to determine the most precise set of molecular constants to date for the B²Σ⁺ and X²Σ⁺ states of ¹²C¹⁶O⁺. Furthermore, we report a rotational analysis of the First Negative bands of ¹³C¹⁶O⁺ for the first time. Several molecular constants characterizing ¹³C¹⁶O⁺ in the B²Σ⁺ and the X²Σ⁺ states, including spin-doubling parameters, have been determined.     

	$\text{T}{}_{\mathrm{e}}$	$\text{ω}{}_{\mathrm{e}}$	$\text{ω}{}_{\mathrm{e}}\text{x}{}_{\mathrm{e}}$
$\text{A}{}_3{}^3\text{Π}{}_2$	16 758	$\text{Δ}\text{G(}\text{1}\text{2}\text{) = 980}$
$\text{A}{}_2{}^3\text{Π}{}_1$	16 442	996	7.0
$\text{A}{}_1{}^3\text{Π}{}_0$	16 131	994	6.5

Extended analysis of the Ar VII spectrum in the vacuum ultraviolet region

The current status of the determination of corrections to the hyperfine splitting of the ground state in hydrogen is considered. Improved calculations are provided taking into account the most recent value for the proton charge radius. Comparing experimental data with predictions for the hyperfine splitting, the Zemach radius of the proton is deduced to be 1.045(16) fm. Employing exponential parametrizations for the electromagnetic form factors we determine the magnetic radius of the proton to be 0.778(29) fm. Both values are compared with the corresponding ones derived from the data obtained in electron-proton scattering experiments and the data extracted from a rescaled difference between the hyperfine splittings in hydrogen and muonium.     

The high-resolution spectrum of the ν1 + ν2 band of NO2: A spin-induced perturbation in the ground state

The spectrum of the ν₁ + ν₂ band of NO₂ has been studied with a resolution of 0.025 cm⁻¹. Spin-rotation constants and rotational constants are reported. An interesting perturbation has been found in the ground state of the molecule which occurs when the K_a = 0 and K_a = 2 levels become accidentally nearly degenerate around N = 42. An explanation of this interaction is presented.     

The laser-induced fluorescence study of AΣ-XΠi band system of CuS

The laser-induced fluorescence excitation spectra of jet-cooled CuS molecules have been recorded in the energy range of 17 200-19 500 cm⁻¹. Fourteen observed vibronic bands have been assigned as three transition progressions: A²Σ⁻ (v′ = 0-4)-X²Π_3/2 (v″ = 0), A²Σ⁻ (v′ = 0-4)-X²Π_3/2 (v″ = 1), and A²Σ⁻ (v′ = 0-3)-X²Π_1/2 (v″ = 0). Spectroscopic constants of both the X²Π ground state and the A²Σ⁻ excited state of ⁶³CuS and ⁶⁵CuS were determined by analyzing their rotationally resolved spectra. Furthermore, the lifetimes of most observed bands were measured for the first time.     

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 high-resolution spectrum of the ν1 (A1) band of 12CD3F

The spectrum of the ν₁ (A₁) band of ¹²CD₃F has been recorded with a resolution of 0.010 cm⁻¹ and deconvolved to 0.005 cm⁻¹. Over 1050 transitions have been assigned with K ≤ 16 and J ≤ 42. The spectrum is highly perturbed, exhibiting avoided crossings in most of the observed sub-bands. The origin of most of the local and global resonances has been determined and the coupling constants estimated. Due to the complexity of the spectrum resulting from the 24 potential interacting states in the region, the assigned frequencies were fitted in a restricted manner (K ≤ 3, J ≤ 15), to obtain the following effective constants for the band: ν₀ = 2090.8118(20) cm⁻¹, α^A = 1.19743 × 10⁻² cm⁻¹, and α^B = −1.8489 × 10⁻³ cm⁻¹. From an unrestricted least-squares analysis, fixing the above parameters the β's (D_v^x = D₀^x − β_v^x) were calculated to be β^J = 1.7776 × 10⁻⁷ cm⁻¹, β^JK = 8.3406 × 10⁻⁷ cm⁻¹, and β^K = −6.3829 × 10⁻⁷ cm⁻¹. These constants serve as good starting parameters for the global analysis necessary to fully analyze the 5-μm region of the ¹²CD₃F spectrum.     

An intermodulated fluorescence study of the A2Σ−-X2Πi band system of copper monoxide

Several lines in the A²Σ⁻(v = 0)-X²Π_i(v = 0) visible band system of gas phase copper monoxide have been measured at sub-Doppler resolution using the technique of intermodulated fluorescence. The copper nuclear magnetic hyperfine splitting is clearly resolved. The observations were fitted to an effective Hamiltonian model and values of the magnetic hyperfine parameters of b_F = −0.0302 cm⁻¹ for the A state and d = 0.0024 cm⁻¹ for the X state were determined. An interpretation of these values in terms of the proposed electronic configurations of these states is presented.     

The A1Π-X1Σ band system of CD+: Spectroscopic constants and isotope shifts

Six bands of the A¹Π-X¹Σ system of CD⁺ in the region 3800–4800 Å have been recorded in emission using an aluminum hollow-cathode discharge in the HeC₂H₂ mixture. From the vibrational and rotational analysis of the observed bands, the following constants (cm^?1) are obtained:

The A3Π-X0+, 1 band system of the SeO molecule

A new weak emission band system of the SeO molecule consisting of 34 band heads degraded to shorter wavelengths has been observed for the first time in the spectral region 6730–8570 Å. The vibrational analysis of the system suggests that it arises from the transition A³Π_reg-X0⁺, 1. All the five subsystems allowed by the selection rule $\text{ΔΩ}\text{= 0}$, ±1 have been identified. The constants in cm^?1 derived for the A³Π state are

Rotational analysis of the a3Π-X1Σ+ bands of GaD

A new method of producing strong and clean emission spectra of the gallium hydride/deuteride molecule has been developed. Five bands belonging to the gallium deuteride molecule (GaD) have been photographed under high resolution. The rotational analyses of the bands lying at 5669.14 Å (0-0) and 5675.10 Å (1-1) in the a³Π₁-X¹Σ⁺ transition, 5761.0 Å (0-0) and 5766.20 Å (1-1) in the a³Π_0⁺-X¹Σ⁺ transition, and 5760.85 Å (0-0) in the a³Π_0⁻-X¹Σ⁺ transition have been performed. Accurate rotational constants (B, D) have been determined for the X¹Σ⁺, a³Π_0^± and a³Π_1^± states. The Λ doubling in the a³Π₀ (v = 0) and a³Π₁ (v = 0 and 1) states are obtained.     

A quasiclassical study of collisions of He with HD(B 1Σ+ u )

A quasiclassical trajectory study has been carried out for collisions of ⁴He with electronically excited H₂(B ¹Σ⁺ _u ) and its isotopomer HD. By using analytical fits for the ab initio potential energy surfaces of the ground and the excited state we have obtained vibrational and electronic quenching cross sections for several initial conditions. We draw the following conclusions. Vibrational excitation strongly promotes electronic quenching whereas translational energy is less effective. Rotational excitation decreases the rate of quenching. In a remarkable contrast to the ground electronic state, vibrational energy transfer on the excited potential energy surface is an efficient and fast process. Collisions at high energies results in T → R energy transfer. The above conclusions are valid for both H₂ and HD.     

Analysis of the bands of the B2Σ+-X2Σ+ transition in 12C16O+ and 13C16O+

The First Negative bands of ¹²C¹⁶O⁺ and ¹³C¹⁶O⁺, in the spectral region 40 000–46 000 cm⁻¹, have been photographed at a resolution sufficient to resolve the spin-doubled components. These data for ¹²C¹⁶O⁺, along with previously reported data of the same transitions, as well as microwave transitions of ¹²C¹⁶O⁺ in the ground state, have been explicitly included in a least-squares fit to determine the most precise set of molecular constants to date for the B²Σ⁺ and X²Σ⁺ states of ¹²C¹⁶O⁺. Furthermore, we report a rotational analysis of the First Negative bands of ¹³C¹⁶O⁺ for the first time. Several molecular constants characterizing ¹³C¹⁶O⁺ in the B²Σ⁺ and the X²Σ⁺ states, including spin-doubling parameters, have been determined.