Rotational and hyperfine analysis of the 0, 0 band of the PrO XX system

The PrO XX 0-0 band is recorded at Doppler-limited resolution by laser excitation spectroscopy with selective fluorescence detection. The rotational and hyperfine structure of this $\text{Ω}\text{′ = 5.5 ?}\text{Ω}\text{″ = 4.5}$ band is reanalyzed. In addition, fluorescence spectra obtained through excitation of selected rotational lines in the XX 0-0 band and by the 529-nm Ar⁺ laser line have established an energy ordering of four low-lying $\text{Ω}\text{= 4.5}$ states and one $\text{Ω}\text{= 6.5}$ state as well as $\text{Δ}\text{G(}\text{1}\text{2}\text{)}$ values for the $\text{Ω}\text{= 6.5}$ and the two lowest $\text{Ω}\text{= 4.5}$ states. Principal constants, in cm^?1, are (1σ uncertainties in parentheses, ¹ indicates constant held fixed):

     

2.

Electronic structure of PrO: An analysis summary     

M. Dulick  R.W. Field 《Journal of Molecular Spectroscopy》1985,113(1):105-141

The (0,0) bands of nine prominent electronic transitions, Systems X, XI, and XVI through XXII, in the wavelength region 500–800 nm were studied. High-precision (±0.005 cm^?1), Doppler-limited, selectively detected cw-dye laser fluorescence excitation spectra for Systems XVI through XXII were recorded and analyzed. Definitive Ω assignments for the upper and lower states of these transitions were established from identified first lines in the P and R branches. Resolved fluorescence studies revealed 22 additional electronic transitions in the same wavelength region, many of which provide energy linkages between the upper or lower states of previously observed transitions. The comprehensive energy level diagram assembled from 31 electronic transition linkages comprises a total of 22 upper and lower electronic levels. Ω assignments and relative energies for the electronic states of the transitions studied (including Systems XIV and IX identified in fluorescence and the proposed assignment for System VI) are

	$\text{T}{}_0$	$\text{Δ}\text{G(}\text{1}\text{2}\text{)}$	$\text{B}{}_0$
$\text{Ω}\text{′ = 5.5}$ (System XXII)	18 944 (1)	—	0.3561
$\text{Ω}\text{′ = 5.5}$ (System XX)	17 845.737 (1)	—	0.355 904 (23)
$\text{Ω}\text{″ = 4.5}$	5 720.5 (10)	—	0.356 (7)
$\text{Ω}\text{″ = 6.5}$	3 736.0 (10)	830.9 (6)	0.362 (7)
$\text{Ω}\text{″ = 4.5}$	3 500.3 (3)	—	0.3556 (3)
$\text{Ω}\text{″ = 4.5}$	1 936.7 (2)	833.0 (4)	0.3637 (2)
$\text{Ω}\text{″ = 4.5}$ (System XX and XXII)	01	831.8 (4)	0.361 918 (22)

     

3.

Continuous wave dye laser excitation spectroscopy CaF A2Πr-X2Σ+     

Robert W. Field  David O. Harris  Takehiko Tanaka 《Journal of Molecular Spectroscopy》1975,57(1):107-117

Excitation spectra for the CaF A²Π-X²Σ(0, 0), (1, 1), and (1, 0) bands have been observed and assigned. The rotational analysis of the CaF A-X and B-X bands by B. S. Mohanty and K. N. Upadhya [Ind. J. Pure Appl. Phys.5, 523 (1967)] is shown to be incorrect. Because it is possible to make independent rotational assignments of each line in an excitation spectrum by observing frequency differences and relative intensities in photoluminescence spectra, tunable laser excitation spectroscopy promises less ambiguity than traditional techniques for assignment of dense, badly overlapped spectra.The following spectroscopic constants (in cm^?1) are obtained for the CaF A²Π and X²Σ states. Numbers in parentheses correspond to three standard deviations uncertainty in the last digit.

System	Ω′	$\text{T′}{}_0\text{(}\text{cm}{}^{\mathrm{?1}}\text{)}$	$\text{Ω″}$	$\text{T″}{}_0\text{(}\text{cm}{}^{\mathrm{?1}}\text{)}$
VI	5.5	11102	4.5	2157
IX	4.5	16597	3.5	3887
X	5.5	13259	4.5	220
XI	5.5	13865	4.5	220
XIV	5.5	16595	4.5	2157
XVI	5.5	19169	4.5	3720
XVII	4.5	16597	3.5	0
XVIII	7.5	21321	6.5	3965
XIX	6.5	19687	5.5	2111
XX	5.5	18069	4.5	220
XXI	4.5	18885	4.5	220
XXII	5.5	19169	4.5	220

     

4.

The ν₃ fundamental band of HDCO     

J.W.C Johns  A.R.W McKellar 《Journal of Molecular Spectroscopy》1977,64(2):327-339

The ν₃ fundamental band (CO stretch) of HDCO at 1724 cm^?1 has been studied using both conventional infrared absorption and CO laser Stark spectroscopy. In addition to the excited-state (v₃ = 1) rotational constants, improved constants for the ground state of HDCO have been obtained by combining previous microwave data with some infrared combination differences. The following constants were determined:

	$\text{X}{}^2\text{Σ}$		$\text{A}{}^2\text{Π}$
$\text{ν}{}_{00}$	0	${}^2\text{Π}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$	16493.1(6)
		${}^2\text{Π}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$	16565.6(6)
$\text{Δ}\text{G(}\text{1}\text{2}\text{)}$	581.1(9)	${}^2\text{Π}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$	586.8(9)
$\text{B}{}_{\mathrm{e}}$	0.3385(11)		0.3436(12)
$\text{B}{}_{\mathrm{e}}\text{(}\text{Ω}\text{=}\text{3}\text{2}\text{) ? B}{}_3\text{(}\text{Ω}\text{=}\text{1}\text{2}\text{)}$	—		0.00312(21)
α	0.00255(48)		0.00283(45)
$\text{D(}\text{estimated}\text{)}$	4.44 × 10?7		4.55 × 10?7
γ(spin-spin)	|γ| < 3 × 10?3		—
$\text{A}{}_0\text{(}\text{spin-orbit}\text{)}$	—		73.4(9)
$\text{p(}\text{lambda doubling}\text{)}$	—		?0.045(4)

     

5.

Laser Stark spectroscopy of formaldehyde-d2: The Coriolis coupled ν4 and ν6 fundamentals     

Dewitt Coffey  Chikashi Yamada  Eizi Hirota 《Journal of Molecular Spectroscopy》1977,64(1):98-108

Using CO₂ and N₂O lasers, we have measured and assigned nineteen ν₄ and nine ν₆ rotation-vibration resonances of the type ΔM = 0 and M = J. These transitions were combined with the zero-field pure rotational spectra in order to determine the two fundamental vibrational frequencies, the rotational constants of both excited states, the Coriolis coupling constant, and the dipole moments of each of the three states. The ground-state rotational constants and centrifugal distortion constants were taken from a microwave study and the centrifugal distortion constants of the excited states were assumed equal to those of the ground state. The following results were obtained (standard deviations in parentheses):

Constant	Ground state	$\text{v}{}_3\text{= 1}$ state	Units
$\text{ν}{}_0$		1724.267	cm?1
$\text{A}$	198 119.75	198 210.4	MHz
$\text{B}$	34 910.646	34 676.6	MHz
$\text{C}$	29 561.488	29 331.3	MHz
$\text{μ}{}_{\mathrm{a}}$	2.3302	2.3486	D
$\text{μ}{}_{\mathrm{b}}$	0.195	0.190	D

     

6.

Fluorescence of the bromine molecules affer selective excitation by a single-mode krypton-lon laser     

G. De Vlieger  F. Claesens  H. Eisendrath 《Journal of Molecular Spectroscopy》1980,83(2):339-342

Optical-optical double-resonance (OODR) spectra of CaF are recorded, with reduced Doppler broadening, using two cw, single-mode dye lasers. Molecular constants for E²Σ⁺ and $\text{E′}{}^2\text{Π}$ are obtained from rotational analysis of the 0-0 and 1-0 E²Σ⁺-A²Π bands and the 0-0 $\text{E′}{}^2\text{Π}\text{-A}{}^2\text{Π}$ band, supplemented by fragmentary observations on the E′-A 0-1 and 1-1 bands:

		$\text{ν}{}_4$		$\text{ν}{}_6$
$\text{ν}{}_0$		938.0345 (6)		989.2519 (18)		(cm?1)
$\text{A}$		139 579 (150)		143 323 (150)		(MHz)
$\text{B}$		31 873.6 (5)		32 379.5 (7)		(MHz)
$\text{C}$		26 242.9 (6)		25 994.4 (8)		(MHz)
$\text{ξ}{}_{64}{}^{\mathrm{(a)}}$			136 178 (770)			(MHz)
μ		2.319 (10)		2.347 (4)		(D)
μ(ground state)			2.3464 (8)			(D)

     

7.

Rotational and vibrational analysis of bands of the f¹Δ-a¹Δ system of titanium oxide     

G.R Brandes  D.C Galehouse 《Journal of Molecular Spectroscopy》1985,109(2):345-351

Five new bands of the f¹Δ-a¹Δ TiO system have been observed in emission between 17774.0 cm^?1 and 19801.0 cm^?1. Rotational and vibrational analyses of the 0-1, 1-0, 1-2, 2-1, and 1-1 bands, as well as a reanalysis of the 0-0 band, yielded the following molecular constants (cm^?1):

				Main parameters
			$\text{E}{}^2\text{Σ}{}^{\mathrm{+}}$		$\text{E′}{}^2\text{Π}$
	$\text{T}{}_0$				34 171.218(2)	34 477.413(3)
	$\text{Δ}\text{G}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$				640.912(3)	668.991(24)
	$\text{B}{}_{\mathrm{<mtext>e</mtext>}}$		0.364393(18)		0.368423(50)
	$\text{α}{}_{\mathrm{<mtext>e</mtext>}}$		0.002266(18)		0.002375(50)
	$\text{A(0)}$			16.483(4)

     

8.

The 10.4 μm CO₂ laser Stark spectra of the ν₄ and the ν₉ bands of 1,1 difluoroethylene     

G Duxbury  H Herman 《Journal of Molecular Spectroscopy》1978,73(3):444-461

The ν₄ and the ν₉ bands of CF₂CH₂ have been studied using coincidences with the 10.4 μm band of the CO₂ laser and the 10.9 μm band of the N₂O laser. These resonances have been analyzed, together with recent microwave results, to give the following vibration-rotation parameters and dipole moments in the ν₄ and ν₉ states

		$\text{f}{}^1\text{Δ}$		$\text{a}{}^1\text{Δ}$
v	$\text{B}{}_{\mathrm{v}}$	$\text{D}{}_{\mathrm{v}}$ (×106)	$\text{B}{}_{\mathrm{v}}$	$\text{D}{}_{\mathrm{v}}$ (×106)
0	0.502277 (17)	0.6411 (57)	0.536168 (20)	0.5938 (76)
1	0.499198 (32)	0.630 (15)	0.533227 (13)	0.5971 (46)
2			0.530335 (26)	0.636 (13)
	$\text{ω}{}_{\mathrm{e}}\text{= 874.104 (4)}$		$\text{ω}{}_{\mathrm{e}}\text{= 1018.273 (4)}$
	$\text{ω}{}_{\mathrm{e}}\text{χ}{}_{\mathrm{e}}\text{= 2.501 (4)}$		$\text{ω}{}_{\mathrm{e}}\text{χ}{}_{\mathrm{e}}\text{= 4.521 (4)}$
	$\text{T′}{}_{\mathrm{e}}\text{?T″}{}_{\mathrm{e}}\text{= 19140.567 (8)}$

     

9.

The electric dipole moment of the hydrogen-bonded heterodimer HCN⋯HF. An investigation of the conditions leading to inadequacy of the second- and fourth-order perturbation theories of the Stark effect for linear molecules     

A.C Legon  D.J Millen  S.C Rogers 《Journal of Molecular Spectroscopy》1978,70(2):209-215

We have detected large deviations of the M_J = 0, J = 2 ← 1 Stark effect transition in the linear molecule HCN?HF from predictions of second-, and even fourth-, order perturbation theory. In order to account satisfactorily for the observed effect it has been necessary to set up and diagonalize the appropriate energy matrix. Smaller deviations in the case of M_J = 1, J = 2 ← 1 have likewise been treated. The values of the electric dipole moment for HCN?HF calculated from these transitions, which show large and small deviations from second-order theory, and from one (M_J = 3, J = 4 ← 3) which shows effectively zero deviation, are now consistent and are as follows:

	$\text{ν}{}_4$ CF2CH2	$\text{ν}{}_9$ CF2CH2
$\text{ν}{}_0$	925.7692 (2)	953.8057 (2)	cm?1
$\text{A}$	10 971.99 (2)	11 026.918 (6)	MHz
$\text{B}$	10 414.98 (2)	10 436.381 (6)	MHz
$\text{C}$	5328.48 (2)	5346.100 (6)	MHz
μ	1.382 (1)	1.382 (1)	D
$\text{μ - μ}{}_0$	0.014 (2)	0.004 (1)	D

     

10.

The vibration-rotation fundamental of NO     

J.W.C. Johns  J. Reid  D.W. Lepard 《Journal of Molecular Spectroscopy》1977,65(1):155-162

The vibration-rotation fundamental of nitric oxide has been reexamined under conditions of moderately high resolution. The new measurements have been combined with earlier measurements on the pure rotation spectrum to give improved vibration-rotation constants. The main results are (in cm^?1)

$\text{J + 1 ← J}$	$\text{M}{}_{\mathrm{J}}$		μ/D
2 ← 1	0		5.627
	1		5.601
4 ← 3	3		5.608
		Mean	5.612

     

11.

Laser Stark spectroscopy in the 9.4-μm region: The ν2 and ν5 bands of methyl chloride-d3     

Chikashi Yamada  Eizi Hirota 《Journal of Molecular Spectroscopy》1977,64(1):31-46

About two hundred Stark resonances of the ν₂ and ν₅ vibration-rotation bands of CD₃³⁵Cl, using a 9.4 μm CO₂ laser as a source, have been measured. By combining these data with the zero-field microwave spectra the following molecular constants have been determined (with the standard deviations in parentheses):

Constant		$\text{v = 0}$		$\text{v = 1}$
ν		0		1875.972 ± 0.001
$\text{A}{}_{\mathrm{<mtext>eff</mtext>}}\text{= A + (0 +}\text{1}\text{2}\text{p)}$		123.1393 ± 0.0030		122.8935 ± 0.0042
$\text{B}{}_{\mathrm{<mtext>eff</mtext>}}\text{= B ?}\text{1}\text{2}\text{q}$		1.696115 ± 0.000011		1.678544 ± 0.000032

     

12.

High-resolution Fourier transform spectroscopy of the ν2 and ν3 fundamentals of nitrosyl fluoride,FNO     

S.C. Foster  J.W.C. Johns 《Journal of Molecular Spectroscopy》1984,103(1):176-186

The ν₂ and ν₃ fundamentals of FNO have been recorded with a Fourier transform spectrophotometer at an apodized resolution of approximately 0.004 cm^?1. The Fourier infrared data have been analyzed together with previous microwave data to yield improved molecular parameters for the (000) and (010) vibrational states and the first set of constants for the (001) state. The main results (in cm^?1) are

		$\text{ν}{}_2$		$\text{ν}{}_5$
$\text{ν}{}_0$		1 028.67275 (15)		1 059.96970 (11)		(cm?1)
$\text{A}$		78 765.20 (89)		78 030.21 (109)		(MHz)
$\text{B}{}^1$		10 805.29 (26)		10 860.10 (13)		(MHz)
$\text{Aζ}{}_5$				?25 080.77 (99)		(MHz)
$\text{D}$			8 756.0 (43)			(MHz)
μ		1.90741 (33)		1.90607 (36)		(D)
μ(ground state)			1.90597 (33)			(D)

     

13.

Laser spectroscopy of CaBr: A²Π-X²Σ⁺ and B²Σ⁺-X²Σ⁺ systems     

P.F. Bernath  R.W. Field  B. Pinchemel  Y. Lefebvre  J. Schamps 《Journal of Molecular Spectroscopy》1981,88(1):175-193

Laser excitation spectra have been recorded for Ca⁷⁹Br and Ca⁸¹Br in the spectral region 600–630 nm. The use of a 1-m monochromator as a narrow band pass filter (1–2 cm^?1) has allowed rotational analysis of the 0-0, 1-1, and 2-2 bands of the B²Σ⁺ - X²Σ⁺ transition and the 0-0 and 1-1 bands of the A²Π - X²Σ⁺ transition. A few additional lines of the 0-1, 1-2, 1-0, and 2-1 bands of the B-X system were used to obtain band origins for vibrational analysis. The main constants for Ca⁷⁹Br are (in cm^?1):

	Ground state	$\text{ν}{}_2$	$\text{ν}{}_3$
A	3.1751882 (17)	3.1861249 (12)	3.1958722 (15)
B	0.39508266 (12)	0.39407878 (14)	0.39211484 (14)
C	0.35051504 (11)	0.34899779 (16)	0.34747411 (14)
$\text{ν}{}_0$	0	765.3551 (4)	519.5980 (4)

     

14.

Vibration-rotation and deperturbation analysis of A²Π-X²Σ⁺ and B²Σ⁺-X²Σ⁺ systems of the CaI molecule     

David E Reisner  Peter F Bernath  R.W Field 《Journal of Molecular Spectroscopy》1981,89(1):107-124

Doppler-limited laser excitation spectroscopy employing narrow-band fluorescence detection was used to obtain a rotational and vibrational analysis in the (0, 0) and (1, 1) bands of the A²Π-X²Σ⁺ system and the (4, 2) (3, 1), (0, 0), (0, 1), (1, 2), (2, 3), and (3, 4) bands of the B²Σ⁺-X²Σ⁺ system of CaI. The A and B states are deperturbed to obtain spectroscopic constants and Franck-Condon factors. Deperturbation was necessary because of the small separation of the A and B states relative to the A ～ B interaction strength and the A²Π spin-orbit splitting. The main deperturbed constants (in cm^?1) are

	$\text{X}{}^2\text{Σ}{}^{\mathrm{+}}$	$\text{A}{}^2\text{Π}$	$\text{B}{}^2\text{Σ}{}^{\mathrm{+}}$
$\text{T}{}_{\mathrm{e}}$	0	15 958.41 (10)	16 383.137 (6)
$\text{ω}{}_{\mathrm{e}}$	285.732 (9)	288.56 (20)	285.747 (9)
$\text{ω}{}_{\mathrm{e}}\text{χ}{}_{\mathrm{e}}$	0.840 (4)	—	0.954 (4)
$\text{B}{}_{\mathrm{e}}$	0.094466141 (30)	0.0957343 (20)	0.0965151 (20)
$\text{α}{}_{\mathrm{e}}$	0.000403551 (40)	0.0004327 (20)	0.0004483 (15)
$\text{γ}{}_{\mathrm{e}}$ (spin-rot.)	0.00301484 (50)	—	0.068767 (79)
$\text{P}{}_{\mathrm{e}}$	—	?0.066834 (64)	—
$\text{A}{}_{\mathrm{e}}$	—	59.175 (1)	—

     

15.

Stark spectroscopy with the CO laser: The ν₂ fundamentals of H₂CO and D₂CO     

J.W.C. Johns  A.R.W. McKellar 《Journal of Molecular Spectroscopy》1973,48(2):354-371

The ν₂ (CO stretching) vibration-rotation bands of H₂CO and D₂CO near 5.8 μm have been studied using the technique of laser Stark spectroscopy. The following vibrational and rotational constants have been determined:

	$\text{X}{}^2\text{Σ}{}^{\mathrm{+}}$	$\text{A}{}^2\text{Π}$	$\text{B}{}^2\text{Σ}{}^{\mathrm{+}}$
$\text{T}{}_{\mathrm{e}}$	0	15 624.67(5)	15 700.52(12)
$\text{ω}{}_{\mathrm{e}}$	238.7496(33)	241.19(7)	242.63(17)
$\text{ω}{}_{\mathrm{e}}\text{χ}{}_{\mathrm{e}}$	0.62789(64)	0.53(5) (Pekeris)	1.17(12) (Pekeris)
$\text{B}{}_{\mathrm{e}}$	0.0693254(84)	0.070460(14)	0.071572(22)
$\text{α}{}_{\mathrm{e}}\text{× 10}{}^4$	2.640(35)	2.15(10)	3.95(2)
$\text{A}{}_{\mathrm{e}}$	—	45.8968(52)	—
$\text{R}{}_{\mathrm{e}}\text{(}\text{A}\text{?}\text{)}$	2.8286(2)	2.8057(3)	2.7839(4)

     

16.

Laser spectroscopy of CuS: Analysis of the A²Σ-X²Π_i system     

F. David  M. Douay  Y. Lefebvre 《Journal of Molecular Spectroscopy》1985,112(1):115-126

Laser excitation spectra of the A²Σ-X²Π_i system have been recorded for ⁶³CuS and ⁶⁵CuS isotopic molecules with a single-mode dye laser operating in the region 17000–18000 cm^?1. For highly overlapped sequences, use of a monochromator as a narrow band filter was necessary to allow rotational analysis. A simultaneous fit of all eight analyzed bands has led to the following spectroscopic constants for ⁶³CuS (in cm^?1):

Constant	H2CO	D2CO	Unit
$\text{ν}{}_0$	1746.011	1701.620	cm?1
$\text{A′}$	281807.8 ± 6.	141696.6 ± 7.	MHz
$\text{B′}$	38608.7 ± 5.	32068.4 ± 7.	MHz
$\text{C′}$	33738.7 ± 3.	25998.6 ± 10.	MHz
μ″	2.328 ± 0.006	2.344 ± 0.006	Debye
μ′	2.344 ± 0.006	2.364 ± 0.005	Debye

     

17.

Optical-optical double-resonance spectroscopy of BaF: The E²Σ⁺ and F²Π states     

Precila C.F Ip  Peter F Bernath  Robert W Field 《Journal of Molecular Spectroscopy》1981,89(1):53-61

Sub-Doppler optical-optical double-resonance excitation spectra of BaF were recorded using two single-mode cw dye lasers. In the 30 000-cm^?1 region, the electronic states observed were E²Σ⁺ and F²Π. The latter had been previously assigned as the “F²Σ⁺” state by Fowler [Phys. Rev.59, 645–652 (1941)]. The (3, 0) and (4, 0) bands of the E²Σ⁺-B²Σ⁺ transition and the (1, 0) and (2, 0) bands of the F²Π-B²Σ⁺ transition were rotationally analyzed. The molecular constants suggest inferences about the dominant atomic orbital character of the Rydberg molecular orbitals responsible for the E²Σ⁺ and F²Π electronic states. A new electronic state, the $\text{E′}{}^2\text{Π}$, is predicted. The molecular parameters obtained (in cm^?1, 1σ uncertainty in parentheses) are

State	$\text{v}$	$\text{T}{}_{\mathrm{v}}$	$\text{B}{}_{\mathrm{v}}$	$\text{D}{}_{\mathrm{v}}\text{× 10}{}^6$	$\text{γ}{}_{\mathrm{v}}$	$\text{p}{}_{\mathrm{v}}$	$\text{a}{}_{\mathrm{v}}\text{× 10}{}^6$
$\text{A}{}^2\text{Σ}{}^{\mathrm{?}}$	0	17924.335 (7)	0.17989 (4)	0.177 (7)	0.03853 (7)
$\text{X}{}^2\text{Π}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$	1	842.574 (7)	0.18701 (4)	0.163 (7)		0.01496 (9)
	0	432.566 (6)	0.18818 (4)	0.162 (7)		0.01508 (9)
$\text{X}{}^2\text{Π}{}_{\mathrm{<mtext>3</mtext><mtext>2</mtext>}}$	1	411.289 (7)	0.18724 (4)	0.184 (7)			?0.96 (6)
	0	—	0.18839 (4)	0.160 (7)			?0.11 (6)

     

18.

The ν₁ and 3ν₁ bands of HNCO     

M. Carlotti  G. di Lonardo  G. Galloni  A. Trombetti 《Journal of Molecular Spectroscopy》1976,62(2):192-200

The infrared absorption of HNCO has been measured in the region of the NH stretching fundamental and in that of the second overtone. The results for the excited states are (in cm^?1):

	$\text{v′}{}_{\mathrm{E}}$	$\text{E}{}^2\text{Σ}{}^{\mathrm{+}}$	$\text{v′}{}_{\mathrm{F}}$	$\text{F}{}^2\text{Π}$
$\text{T}{}_{\mathrm{v\prime 0}}$	3	29 767.32(1)	1	29 997.29(1)
$\text{Δ}\text{G}{}_{\mathrm{<mtext>v\prime \; +\; </mtext><mtext>1</mtext><mtext>2</mtext>}}$	3	522.841(27)	1	522.553(2)
$\text{B}{}_{\mathrm{e}}$		0.22990(22)		0.22931(8)
$\text{α}{}_{\mathrm{e}}$		0.00113(14)		0.00108(2)
$\text{A}{}_{\mathrm{v\prime }}$			1	56.9840(12)
$\text{p}{}_{\mathrm{v\prime }}$			1	?0.02426(6)
$\text{γ}{}_{\mathrm{v\prime }}$	3	?0.17367(46)

     

19.

The absorption spectrum of the Ag₂ molecule     

C.M Brown  M.L Ginter 《Journal of Molecular Spectroscopy》1978,69(1):25-36

The high dispersion absorption spectrum of the Ag₂ molecule has been photographed in the ～5300–1500-Å region. Observations include the previously reported A ← X, B ← X, C ← X, D ← X, and E ← X transitions and a new H ← X transition which occurs in the vacuum ultraviolet. Extensive spectral blending precluded detailed rotational analyses, but the band structures are consistent with $\text{ΔΩ}\text{= 0}$ and $\text{ΔΩ}\text{≥1}$ for D-X and C-X, respectively. The H state is perturbed and probably predissociated. The following molecular constants (in cm^?1) were obtained from fitting bandhead data to the usual expressions:

Band	$\text{ν}{}_0$	$\text{A-}\text{B}$	B	C
$\text{ν}{}_1$	3533.1	27.0	—	—
$\text{3ν}{}_1$	10145.79	22.6713	0.368426	0.361722

     

20.

Rotational analysis of some electronic transitions in the spectrum of PrO     

E.A. Shenyavskaya  L.A. Kaledin 《Journal of Molecular Spectroscopy》1982,91(1):22-34

Rotational analysis of 13 emission bands of PrO belonging to 10 different systems was carried out. The derived constants are as follows:

State	Te	ωc	Xωt
X	0.0	192.0	0.58
B	35 838.6	151.8	0.87
C	37 631.6	171.0	0.84
D	39 014.5	168.2	1.20
E	40 159.9	146.1	1.58
H	58 273.1	165.9	2.46

     

$\text{ν}{}_0$	$\text{B′}$	$\text{D′ × 10}{}^7$	$\text{B″}$	$\text{D″ × 10}{}^7$
18 665.19(1)	0.3530(1)	1.80(5)	0.3622(1)	2.85(1)
18 613.22(1)	0.3517(1)	0.4(3)	0.3606(1)	2.4(2)
17 842.32(1)	0.3560(1)	3.0(1)	0.3621(1)	2.7(1)
17 796.09(4)	0.3532(3)	2.4(8)	0.3604(2)	2.7(6)
18 628.22(3)	0.3530(6)	1.8(8)	0.3620(5)	2.7(7)
14 426.12(2)	0.3519(1)	5.5(6)	0.3620(1)	1.9(6)
13 541.44(2)	0.3500(2)	3.7(5)	0.3605(2)	2.3(5)
13 645.78(8)	0.3511(3)	3.1(5)	0.3620(2)	2.8(5)
12 961.98(4)	0.3445(4)	4.5(4)	0.3603(3)	2.3(7)
9 600.47(1)	0.3454(1)	2.8(2)	0.3620(1)	3.0(3)
16 591.29(1)	0.3536(1)	0.5(2)	0.3610(1)	2.6(1)
11 912.89(1)	0.3480(2)	8.5(8)	0.3610(1)	2.2(6)
10 429.62(2)	0.3450(1)	3.1(1)	0.3610(1)	3.0(3)

Electronic structure of PrO: An analysis summary

The (0,0) bands of nine prominent electronic transitions, Systems X, XI, and XVI through XXII, in the wavelength region 500–800 nm were studied. High-precision (±0.005 cm^?1), Doppler-limited, selectively detected cw-dye laser fluorescence excitation spectra for Systems XVI through XXII were recorded and analyzed. Definitive Ω assignments for the upper and lower states of these transitions were established from identified first lines in the P and R branches. Resolved fluorescence studies revealed 22 additional electronic transitions in the same wavelength region, many of which provide energy linkages between the upper or lower states of previously observed transitions. The comprehensive energy level diagram assembled from 31 electronic transition linkages comprises a total of 22 upper and lower electronic levels. Ω assignments and relative energies for the electronic states of the transitions studied (including Systems XIV and IX identified in fluorescence and the proposed assignment for System VI) are

Continuous wave dye laser excitation spectroscopy CaF A2Πr-X2Σ+

Excitation spectra for the CaF A²Π-X²Σ(0, 0), (1, 1), and (1, 0) bands have been observed and assigned. The rotational analysis of the CaF A-X and B-X bands by B. S. Mohanty and K. N. Upadhya [Ind. J. Pure Appl. Phys.5, 523 (1967)] is shown to be incorrect. Because it is possible to make independent rotational assignments of each line in an excitation spectrum by observing frequency differences and relative intensities in photoluminescence spectra, tunable laser excitation spectroscopy promises less ambiguity than traditional techniques for assignment of dense, badly overlapped spectra.The following spectroscopic constants (in cm^?1) are obtained for the CaF A²Π and X²Σ states. Numbers in parentheses correspond to three standard deviations uncertainty in the last digit.

The ν3 fundamental band of HDCO

The ν₃ fundamental band (CO stretch) of HDCO at 1724 cm^?1 has been studied using both conventional infrared absorption and CO laser Stark spectroscopy. In addition to the excited-state (v₃ = 1) rotational constants, improved constants for the ground state of HDCO have been obtained by combining previous microwave data with some infrared combination differences. The following constants were determined:

Laser Stark spectroscopy of formaldehyde-d2: The Coriolis coupled ν4 and ν6 fundamentals

Using CO₂ and N₂O lasers, we have measured and assigned nineteen ν₄ and nine ν₆ rotation-vibration resonances of the type ΔM = 0 and M = J. These transitions were combined with the zero-field pure rotational spectra in order to determine the two fundamental vibrational frequencies, the rotational constants of both excited states, the Coriolis coupling constant, and the dipole moments of each of the three states. The ground-state rotational constants and centrifugal distortion constants were taken from a microwave study and the centrifugal distortion constants of the excited states were assumed equal to those of the ground state. The following results were obtained (standard deviations in parentheses):

Fluorescence of the bromine molecules affer selective excitation by a single-mode krypton-lon laser

Optical-optical double-resonance (OODR) spectra of CaF are recorded, with reduced Doppler broadening, using two cw, single-mode dye lasers. Molecular constants for E²Σ⁺ and $\text{E′}{}^2\text{Π}$ are obtained from rotational analysis of the 0-0 and 1-0 E²Σ⁺-A²Π bands and the 0-0 $\text{E′}{}^2\text{Π}\text{-A}{}^2\text{Π}$ band, supplemented by fragmentary observations on the E′-A 0-1 and 1-1 bands:

Rotational and vibrational analysis of bands of the f1Δ-a1Δ system of titanium oxide

Five new bands of the f¹Δ-a¹Δ TiO system have been observed in emission between 17774.0 cm^?1 and 19801.0 cm^?1. Rotational and vibrational analyses of the 0-1, 1-0, 1-2, 2-1, and 1-1 bands, as well as a reanalysis of the 0-0 band, yielded the following molecular constants (cm^?1):

The 10.4 μm CO2 laser Stark spectra of the ν4 and the ν9 bands of 1,1 difluoroethylene

The ν₄ and the ν₉ bands of CF₂CH₂ have been studied using coincidences with the 10.4 μm band of the CO₂ laser and the 10.9 μm band of the N₂O laser. These resonances have been analyzed, together with recent microwave results, to give the following vibration-rotation parameters and dipole moments in the ν₄ and ν₉ states

The electric dipole moment of the hydrogen-bonded heterodimer HCN⋯HF. An investigation of the conditions leading to inadequacy of the second- and fourth-order perturbation theories of the Stark effect for linear molecules

We have detected large deviations of the M_J = 0, J = 2 ← 1 Stark effect transition in the linear molecule HCN?HF from predictions of second-, and even fourth-, order perturbation theory. In order to account satisfactorily for the observed effect it has been necessary to set up and diagonalize the appropriate energy matrix. Smaller deviations in the case of M_J = 1, J = 2 ← 1 have likewise been treated. The values of the electric dipole moment for HCN?HF calculated from these transitions, which show large and small deviations from second-order theory, and from one (M_J = 3, J = 4 ← 3) which shows effectively zero deviation, are now consistent and are as follows:

The vibration-rotation fundamental of NO

The vibration-rotation fundamental of nitric oxide has been reexamined under conditions of moderately high resolution. The new measurements have been combined with earlier measurements on the pure rotation spectrum to give improved vibration-rotation constants. The main results are (in cm^?1)

Laser Stark spectroscopy in the 9.4-μm region: The ν2 and ν5 bands of methyl chloride-d3

About two hundred Stark resonances of the ν₂ and ν₅ vibration-rotation bands of CD₃³⁵Cl, using a 9.4 μm CO₂ laser as a source, have been measured. By combining these data with the zero-field microwave spectra the following molecular constants have been determined (with the standard deviations in parentheses):

High-resolution Fourier transform spectroscopy of the ν2 and ν3 fundamentals of nitrosyl fluoride,FNO

The ν₂ and ν₃ fundamentals of FNO have been recorded with a Fourier transform spectrophotometer at an apodized resolution of approximately 0.004 cm^?1. The Fourier infrared data have been analyzed together with previous microwave data to yield improved molecular parameters for the (000) and (010) vibrational states and the first set of constants for the (001) state. The main results (in cm^?1) are

Laser spectroscopy of CaBr: A2Π-X2Σ+ and B2Σ+-X2Σ+ systems

Laser excitation spectra have been recorded for Ca⁷⁹Br and Ca⁸¹Br in the spectral region 600–630 nm. The use of a 1-m monochromator as a narrow band pass filter (1–2 cm^?1) has allowed rotational analysis of the 0-0, 1-1, and 2-2 bands of the B²Σ⁺ - X²Σ⁺ transition and the 0-0 and 1-1 bands of the A²Π - X²Σ⁺ transition. A few additional lines of the 0-1, 1-2, 1-0, and 2-1 bands of the B-X system were used to obtain band origins for vibrational analysis. The main constants for Ca⁷⁹Br are (in cm^?1):

Vibration-rotation and deperturbation analysis of A2Π-X2Σ+ and B2Σ+-X2Σ+ systems of the CaI molecule

Doppler-limited laser excitation spectroscopy employing narrow-band fluorescence detection was used to obtain a rotational and vibrational analysis in the (0, 0) and (1, 1) bands of the A²Π-X²Σ⁺ system and the (4, 2) (3, 1), (0, 0), (0, 1), (1, 2), (2, 3), and (3, 4) bands of the B²Σ⁺-X²Σ⁺ system of CaI. The A and B states are deperturbed to obtain spectroscopic constants and Franck-Condon factors. Deperturbation was necessary because of the small separation of the A and B states relative to the A ～ B interaction strength and the A²Π spin-orbit splitting. The main deperturbed constants (in cm^?1) are

Stark spectroscopy with the CO laser: The ν2 fundamentals of H2CO and D2CO

The ν₂ (CO stretching) vibration-rotation bands of H₂CO and D₂CO near 5.8 μm have been studied using the technique of laser Stark spectroscopy. The following vibrational and rotational constants have been determined:

Laser spectroscopy of CuS: Analysis of the A2Σ-X2Πi system

Laser excitation spectra of the A²Σ-X²Π_i system have been recorded for ⁶³CuS and ⁶⁵CuS isotopic molecules with a single-mode dye laser operating in the region 17000–18000 cm^?1. For highly overlapped sequences, use of a monochromator as a narrow band filter was necessary to allow rotational analysis. A simultaneous fit of all eight analyzed bands has led to the following spectroscopic constants for ⁶³CuS (in cm^?1):

Optical-optical double-resonance spectroscopy of BaF: The E2Σ+ and F2Π states

Sub-Doppler optical-optical double-resonance excitation spectra of BaF were recorded using two single-mode cw dye lasers. In the 30 000-cm^?1 region, the electronic states observed were E²Σ⁺ and F²Π. The latter had been previously assigned as the “F²Σ⁺” state by Fowler [Phys. Rev.59, 645–652 (1941)]. The (3, 0) and (4, 0) bands of the E²Σ⁺-B²Σ⁺ transition and the (1, 0) and (2, 0) bands of the F²Π-B²Σ⁺ transition were rotationally analyzed. The molecular constants suggest inferences about the dominant atomic orbital character of the Rydberg molecular orbitals responsible for the E²Σ⁺ and F²Π electronic states. A new electronic state, the $\text{E′}{}^2\text{Π}$, is predicted. The molecular parameters obtained (in cm^?1, 1σ uncertainty in parentheses) are

The ν1 and 3ν1 bands of HNCO

The infrared absorption of HNCO has been measured in the region of the NH stretching fundamental and in that of the second overtone. The results for the excited states are (in cm^?1):

The absorption spectrum of the Ag2 molecule

The high dispersion absorption spectrum of the Ag₂ molecule has been photographed in the ～5300–1500-Å region. Observations include the previously reported A ← X, B ← X, C ← X, D ← X, and E ← X transitions and a new H ← X transition which occurs in the vacuum ultraviolet. Extensive spectral blending precluded detailed rotational analyses, but the band structures are consistent with $\text{ΔΩ}\text{= 0}$ and $\text{ΔΩ}\text{≥1}$ for D-X and C-X, respectively. The H state is perturbed and probably predissociated. The following molecular constants (in cm^?1) were obtained from fitting bandhead data to the usual expressions:

Rotational analysis of some electronic transitions in the spectrum of PrO

Rotational analysis of 13 emission bands of PrO belonging to 10 different systems was carried out. The derived constants are as follows: