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Constants of diatomic molecules

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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Data compiled by: Klaus P. Huber and Gerhard H. Herzberg

Data collected through March, 1977

Symbols used in the table of constants
State electronic state and / or symmetry symbol
Te minimum electronic energy (cm-1)
ωe vibrational constant – first term (cm-1)
ωexe vibrational constant – second term (cm-1)
ωeye vibrational constant – third term (cm-1)
Be rotational constant in equilibrium position (cm-1)
αe rotational constant – first term (cm-1)
γe rotation-vibration interaction constant (cm-1)
De centrifugal distortion constant (cm-1)
βe rotational constant – first term, centrifugal force (cm-1)
re internuclear distance (Å)
Trans. observed transition(s) corresponding to electronic state
ν00 position of 0-0 band (units noted in table)
Diatomic constants for 14N16O++
Three states (A, B, C) or unresolved groups of states observed by double charge transfer spectroscopy Appell, Durup, et al., 1973; reasonable agreement with theoretical predictions Thulstrup, Thulstrup, et al., 1974.
C 64000           
B (2Sigma+) 25000           
A (2Pi) 0           
X (2Sigma+) 0           


1D00(NO) + I.P.(O) - I.P.(NO).
2Average of two values obtained by electron impact mass spectrometry Dorman and Morrison, 1961 and double charge transfer spectroscopy Appell, Durup, et al., 1973. A similar value (30.8 eV) can be derived from Auger electron spectra Moddeman, Carlson, et al., 1971, but the assignments are highly tentative and can also be interpreted as indicating an ionization potential of only ~26 eV.
3The 1sN and 1s0 1Pi - 3Pi splittings are 1.41 and 0.53 eV, respectively Davis and Shirley, 1972, Davis, Martin, et al., 1973. The 1sN photoelectron peaks have an anomalous intensity ratio of 3.43 Bagus, Schrenk, et al., 1974; theoretical interpretation Hillier and Kendrick, 1975, Darko, Hillier, et al., 1977. Predicted 1sN satellite ("shake-up") peaks Hillier and Kendrick, 1975.
4Long vibrational progression in the photoelectron spectrum at ~23 eV Edqvist, Lindholm, et al., 1970, Edqvist, Asbrink, et al., 1971; neither the vibrational numbering nor the assignment to B' 1Sigma+ are certain. Lefebvre-Brion, 1971 suggests a mixed 1Pi state resulting from configuration interaction between states arising from ...4sigma 5sigma2 lpi4 2pi (like c 3Pi) and ...4sigma2 5sigma 1pi3 2pi2. See also Thulstrup and Ohrn, 1972, Thulstrup, Thulstrup, et al., 1974.
5Limit of the Narayana-Price Rydberg series. Single strong peak in the photoelectron spectrum at 21.72 eV Price, 1968, Samson, 1968, Edqvist, Lindholm, et al., 1970, Edqvist, Asbrink, et al., 1971. The high-energy wing is overlapped by weak unresolved structure (w ~ 400) tentatively attributed to the corresponding 1Pi state by Edqvist, Asbrink, et al., 1971; see, however, 4. Predissociation into N+ + O Hertz, Jochims, et al., 1974.
6Limit of Tanaka's gamma Rydberg series. Short progression in the photoelectron spectrum Turner and May, 1966, Price, 1968, Edqvist, Lindholm, et al., 1970, Edqvist, Asbrink, et al., 1971; see 7.
7Franck-Condon factors for ionizing transitions from X 2Pi Wacks, 1964, Halmann and Laulicht, 1965, Spohr and Puttkamer, 1967, Nicholls, 1968, Field, 1973, Coxon, Clyne, et al., 1975.
8Perturbations by b' 3Sigma- Miescher, 1955, Field, 1973, Alberti and Douglas, 1975.
9Radiative lifetime tau(v=0)= 56 ns Hesser and Dressler, 1966, Hesser, 1968; f00 = 0.00025. Variation of transition moment with r Aarts and de Heer, 1971, Mentall and Morgan, 1972, Stone and Zipf, 1972.
10Franck-Condon factors Nicholls, 1968, Wentink and Spindler, 1970, Coxon, Clyne, et al., 1975.
11Long upper state progression in the photoelectron spectrum Edqvist, Lindholm, et al., 1970, Edqvist, Asbrink, et al., 1971; see 7.
12Interpolated using data for CO and N2 Field, 1973.
13Adjusted to give agreement with B5 = 1.2512 Field, 1973 as obtained from a perturbation analysis Field, 1973.
14Fragments in emission from perturbed A 1Pi ~ b' 3Sigma- levels.
15Limit of Tanaka's beta Rydberg series. Very short progression in the photoelectron spectrum Turner and May, 1966, Price, 1968, Edqvist, Lindholm, et al., 1970, Edqvist, Asbrink, et al., 1971; see 7.
16Quadrupole moment of NO+ Qm= +0.79E-26 esu cm2 Jungen and Miescher, 1969; see also Jungen and Lefebvre-Brion, 1970, Billingsley and Krauss, 1974.
17Observed in the IR spectrum of hot air resulting from a high altitude nuclear detonation; the 1-0 and 2-0 bands have been identified. Theoretical intensities Billingsley, 1973.


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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Appell, Durup, et al., 1973
Appell, J.; Durup, J.; Fehsenfeld, F.C.; Fournier, P., Double charge transfer spectroscopy of diatomic molecules, J. Phys. B:, 1973, 6, 197. [all data]

Thulstrup, Thulstrup, et al., 1974
Thulstrup, P.W.; Thulstrup, E.W.; Andersen, A.; Ohrn, Y., Configuration interaction calculations of some observed states of NO-, NO, NO+, and NO2+, J. Chem. Phys., 1974, 60, 3975. [all data]

Dorman and Morrison, 1961
Dorman, F.H.; Morrison, J.D., Double and triple ionization in molecules induced by electron impact, J. Chem. Phys., 1961, 35, 575. [all data]

Moddeman, Carlson, et al., 1971
Moddeman, W.E.; Carlson, T.A.; Krause, M.O.; Pullen, B.P.; Bull, W.E.; Schweitzer, G.K., Determination of the K-LL Auger spectra of N2, O2, CO, NO, H2O, and CO2, J. Chem. Phys., 1971, 55, 2317. [all data]

Davis and Shirley, 1972
Davis, D.W.; Shirley, D.A., Splitting in nitrogen and oxygen 1s photoelectron peaks in two paramagnetic molecules: spin density implications, J. Chem. Phys., 1972, 56, 669. [all data]

Davis, Martin, et al., 1973
Davis, D.W.; Martin, R.L.; Banna, M.S.; Shirley, D.A., Multiplet splitting in 1s hole status of molecules, J. Chem. Phys., 1973, 59, 4235. [all data]

Bagus, Schrenk, et al., 1974
Bagus, P.S.; Schrenk, M.; Davis, D.W.; Shirley, D.A., Anomalous multiplet-splitting intensity ratios in K-level x-ray photoemission spectra of NO and O2, Phys. Rev. A: Gen. Phys., 1974, 9, 1090. [all data]

Hillier and Kendrick, 1975
Hillier, I.H.; Kendrick, J., Multiplet splitting and intensity ration in the N(ls) photoemission spectrum of NO, J. Chem. Soc. Faraday Trans. 2, 1975, 71, 1654. [all data]

Darko, Hillier, et al., 1977
Darko, T.; Hillier, I.H.; Kendrick, J., Correlation effects in the nitrogen 1s photoelectron spectrum of nitric oxide, Chem. Phys. Lett., 1977, 45, 188. [all data]

Edqvist, Lindholm, et al., 1970
Edqvist, O.; Lindholm, E.; Selin, L.E.; Sjogren, H.; Asbrink, L., Rydberg series in small molecules. VII. Rydberg series and photoelectron spectroscopy of NO, Ark. Fys., 1970, 40, 439. [all data]

Edqvist, Asbrink, et al., 1971
Edqvist, O.; Asbrink, L.; Lindholm, E., On the photoelectron spectrum of NO, Z. Naturforsch. A:, 1971, 26, 1407. [all data]

Lefebvre-Brion, 1971
Lefebvre-Brion, H., Intensity anomaly in the photoelectron spectrum of NO, Chem. Phys. Lett., 1971, 9, 463. [all data]

Thulstrup and Ohrn, 1972
Thulstrup, E.W.; Ohrn, Y., Configuration interaction studies of NO and NO+ with comparisons to photoelectron spectra, J. Chem. Phys., 1972, 57, 3716. [all data]

Price, 1968
Price, W.C., Developments in Photo-Electron Spectroscopy in Molecular Spectroscopy, Hepple, ed(s)., The Institute of Petroleum, London, 1968, 221-236. [all data]

Samson, 1968
Samson, J.A.R., Higher ionization potentials of nitric oxide, Phys. Letters, 1968, 28A, 391. [all data]

Hertz, Jochims, et al., 1974
Hertz, H.; Jochims, H.W.; Schenk, H.; Sroka, W., The influence of the Rydberg states (2s«sigma»*-1)nd«pi» and (2s«sigma»*-1)np«pi»«sigma» on the formation of NO+, N+, O+ and N by photon impact on NO, Chem. Phys. Lett., 1974, 29, 572. [all data]

Turner and May, 1966
Turner, D.W.; May, D.P., Franck-Condon factors in ionization: experimental measurement using molecular photoelectron spectroscopy, J. Chem. Phys., 1966, 45, 471. [all data]

Wacks, 1964
Wacks, M.E., Franck-Condon factors for the ionization of CO, NO, and O2, J. Chem. Phys., 1964, 41, 930. [all data]

Halmann and Laulicht, 1965
Halmann, M.; Laulicht, I., Isotope effects on vibrational transition probabilities. III. Ionization of isotopic H2, N2,,O2, NO, CO, and HCl molecules, J. Chem. Phys., 1965, 43, 1503. [all data]

Spohr and Puttkamer, 1967
Spohr, R.; Puttkamer, E.v., Energiemessung von Photoelektronen und Franck-Condon-Faktoren der Schwingungsubergange einiger Molekulionen, Z. Naturforsch., 1967, 22a, 705. [all data]

Nicholls, 1968
Nicholls, R.W., Franck-Condon factors for ionizing transitions of O2, CO, NO and H2 and for the NO+(A1-«SIGMA»x1«SIGMA») band system, J. Phys. B:, 1968, 1, 1192. [all data]

Field, 1973
Field, R.W., The valence states of NO+, J. Mol. Spectrosc., 1973, 47, 194. [all data]

Coxon, Clyne, et al., 1975
Coxon, J.A.; Clyne, M.A.A.; Setser, D.W., Penning ionization optical spectroscopy: metastable helium (He 23S) with nitric oxide, Chem. Phys., 1975, 7, 255. [all data]

Miescher, 1955
Miescher, E., Fine structure of NO+ and NO emission spectra in the Schumann region, Can. J. Phys., 1955, 33, 355. [all data]

Alberti and Douglas, 1975
Alberti, F.; Douglas, A.E., Laboratory determination of the frequencies of possible interstellar lines of NO+, Can. J. Phys., 1975, 53, 1179. [all data]

Hesser and Dressler, 1966
Hesser, J.E.; Dressler, K., Radiative lifetimes of ultraviolet molecular transitions, J. Chem. Phys., 1966, 45, 3149. [all data]

Hesser, 1968
Hesser, J.E., Absolute Transition Probabilities in Ultraviolet Molecular Spectra, J. Chem. Phys., 1968, 48, 6, 2518, https://doi.org/10.1063/1.1669477 . [all data]

Aarts and de Heer, 1971
Aarts, J.F.M.; de Heer, F.J., Emission cross sections of the A1«PI» state of NO+, Physica (Amsterdam), 1971, 54, 609. [all data]

Mentall and Morgan, 1972
Mentall, J.E.; Morgan, H.D., Vacuum-ultraviolet excitation cross sections by electron impact on NO, J. Chem. Phys., 1972, 56, 2271. [all data]

Stone and Zipf, 1972
Stone, E.J.; Zipf, E.C., Electron-impact excitation of nitric oxide, J. Chem. Phys., 1972, 56, 2870. [all data]

Wentink and Spindler, 1970
Wentink, T., Jr.; Spindler, R.J., Jr., Franck-Condon Factors and r-centroids for No+, CP, SiF, BF, BCl, and BBr, J. Quant. Spectrosc. Radiat. Transfer, 1970, 10, 609. [all data]

Jungen and Miescher, 1969
Jungen, C.; Miescher, E., Absorption spectrum of the NO molecule. IX. The structure of the f complexes, the ionization potential of NO, and the quadrupole moment of NO+, Can. J. Phys., 1969, 47, 1769. [all data]

Jungen and Lefebvre-Brion, 1970
Jungen, Ch.; Lefebvre-Brion, H., The quadrupole moment of NO+, J. Mol. Spectrosc., 1970, 33, 520. [all data]

Billingsley and Krauss, 1974
Billingsley, F.P., II; Krauss, M., Quadrupole moment of CO, N2, and NO+, J. Chem. Phys., 1974, 60, 2767. [all data]

Billingsley, 1973
Billingsley, F.P., II, Calculation of the absolute infrared intensities for the 0-1, 0-2 and 1-2 vibration-rotation transitions in the ground state of NO+, Chem. Phys. Lett., 1973, 23, 160. [all data]


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