chan_1994#
W. F. Chan, G. Cooper and C. E. Brion, “Discrete and continuum photoabsorption oscillator strengths for the electronic spectrum of nitrous oxide (5.5-203 eV)”, Chem. Phys. 180, 77 (1994)
Source record · Catalogue · Review register
DOI: 10.1016/0301-0104(93)e0386-a
Source kind: measurement
Recorded technique: Dipole (e,e) spectroscopy. Low resolution (about 1 eV FWHM, 8 keV, zero mean scattering angle): energy-loss spectra at 7.4-39.9, 40.0-79.3 and 80-203 eV at about 0.5, 1 and 2 eV intervals, Bethe-Born converted; the valence-shell fraction above 203 eV from a fit A E^-2 + B E^-3 + C E^-4 to 90-203 eV (7.1 %); the whole TRK-normalised to 16.51 (16 valence electrons plus 0.51 for Pauli-excluded K-shell transitions) (pp. 2-5). High resolution (0.048 eV FWHM, 3 keV): 5.5-30 eV, Bethe-Born converted and normalised at 26 eV to the low-resolution value; band and interval strengths by integrating the spectrum over energy ranges (pp. 7-11). Independent of optical data and target density; no line saturation. Background removed by quartering the sample pressure; energy scale from helium’s 21.218 eV line. Linde N2O, 99 % (p. 3).
Materials in structured entries: N2O
Dataset quantities: differential_oscillator_strength, interval_oscillator_strength, oscillator_strength
Contents: 8 datasets; 1 formula.
Curation notes#
Values per molecule; no density or state involved (room-temperature N2O, not stated). Uncertainty (p. 4): ‘The uncertainty of the present measurements is estimated to be +-5%, arising from use of the TRK sum-rule ... to determine the absolute scale, uncertainties in the determination of the kinematic Bethe-Born factors for each spectrometer, and the background subtraction procedures’. A small sharp peak at 12.94 eV (Figs. 4, 7) is ‘likely due to very small nitrogen impurity’ (p. 7).
Table 1 (p. 4): the low-resolution df/dE, 7.40-203.00 eV, 164 points (sigma(Mb) = 109.75 df/dE(eV^-1)). Two energies are misprinted (errata): 129.28 and 131.23 for 129.23 and 131.28 (the grid steps 2.05 eV, 127.18 ... 133.33, as in the carbon dioxide paper’s Table 1, chan_1993_co2). Comparisons (pp. 5-6): Shaw et al. (1992) slightly higher at 20-25.83 eV; Lee et al. (1973) slightly lower at 20-25 eV, slightly higher at 40-50 eV; Cole and Dexter 10-15 % lower; De Reilhac and Damany significantly lower; Hitchcock et al. and Brion and Tan (normalised to Lee et al.) slightly higher. Sums computed from Table 1 (2026-09-27; trapezoid from 7.40 eV plus the paper’s tail, the formula below): S(0) = 15.341 over 7.40-203 eV and 16.509 in all (normalisation 16.51; tail 7.08 %, printed 7.1 %); S(-1) = 14.254, S(-2) = 19.319 au, S(-3) = 34.02, S(-4) = 70.57, S(-6) = 401.9. Olney et al. (olney_1997 table1_N2O) quote 20.23 au for the S(-2) of ‘the originally published’ spectrum, 4.7 % above this table’s 19.32 (the CO, N2 and CO2 values of Olney’s Table 1 agree with the corresponding Chan tables to 1 %): a finding, unexplained here. The paper prints no S(k).
Table 2 (p. 8): the three dissociative continuum bands below 10 eV integrated over the ranges printed in its header (B 1Delta 5.70-7.70, C 1Pi 7.70-8.97, D 1Sigma+ 8.97-10.23 eV): the present values and Lee and Suto’s (digitised from their figure and integrated over the same ranges by Chan et al., p. 9) as interval data; the others (Huebner et al., Rabalais et al., Zelikoff et al., and Chutjian and Segal’s INDO theory) as band values (rows B, C, D), their own ranges not being stated (Zelikoff et al.’s, in zelikoff_1953, differ). Rabalais et al.’s C 1Pi value 0.007 ‘is likely to be incorrect’ (p. 9). Table 3 (p. 11): 35 intervals, 10.23-16.40 eV, present and Huebner et al. (100 eV impact energy; ‘in general about 10%-15% higher’). The present intervals 5.70-16.40 eV (Tables 2 and 3) are one dataset; the Table 3 intervals sum to 1.543 (the low-resolution Table 1 gives about 1.62 over the same range), the Table 2 bands to 0.402 (Table 1: 0.376 to 10.23 eV).
zelikoff_1953 (curated) holds the same Zelikoff et al. band strengths (0.0015, 0.0211, 0.367; its continuum_f): the Zelikoff dataset here is reproduced from it.
Recorded bibliographic identity status: VALIDATED_WITH_WARNINGS. This concerns identification of the source; it does not establish the scientific correctness of its contents.
Datasets#
chan_1994/continuum#
{
"id": "continuum",
"material": "N2O",
"file": "N2O/chan_1994__continuum.csv",
"table": "tbl_b536b17df805",
"quantity": "differential_oscillator_strength",
"unit": "1/eV",
"scale": 0.01,
"abscissa_unit": "eV",
"use": "primary",
"uncertainty": {
"relative": 0.05,
"level": "not stated"
}
}
Table 1: low-resolution (1 eV FWHM) dipole (e,e) absolute df/dE (10^-2 eV^-1), 7.40-203.00 eV, 164 points in print order (about 0.51 eV steps to 39.86 eV, 1.03 eV to 79.28 eV, 2.05 eV to 203 eV); TRK-normalised to 16.51 with the fitted tail above 203 eV (formula tail_fit). Two energies corrected by errata. Uncertainty +-5 % (p. 4).
chan_1994/intervals_present#
{
"id": "intervals_present",
"material": "N2O",
"file": "N2O/chan_1994__intervals_present.csv",
"table": "tbl_c3cbc336c3cb, tbl_989c4d1b6636",
"quantity": "interval_oscillator_strength",
"abscissa_unit": "eV",
"columns": {
"x_upper": "eV"
},
"use": "primary",
"uncertainty": {
"relative": 0.05,
"level": "not stated"
}
}
Tables 2 and 3 ‘present work’: the high-resolution (0.048 eV) oscillator strength integrated over the B 1Delta (5.70-7.70 eV), C 1Pi (7.70-8.97 eV) and D 1Sigma+ (8.97-10.23 eV) continuum bands (Table 2) and over 35 intervals from 10.23 to 16.40 eV (Table 3); row = the range, x and x_upper its edges; contiguous. Uncertainty +-5 % (p. 4).
chan_1994/bands_lee_1984#
{
"id": "bands_lee_1984",
"material": "N2O",
"file": "N2O/chan_1994__bands_lee_1984.csv",
"table": "tbl_c3cbc336c3cb",
"quantity": "interval_oscillator_strength",
"abscissa_unit": "eV",
"columns": {
"x_upper": "eV"
},
"use": "reproduced",
"reproduced_from": [
"L. C. Lee and M. Suto, J. Chem. Phys. 80, 4718 (1984)"
]
}
Table 2: Lee and Suto’s photoabsorption, ‘obtained by integrating the data as digitized from the figure reported in the original paper’ over the header’s ranges (C 1Pi 7.70-8.97, D 1Sigma+ 8.97-10.23 eV) by Chan et al. (p. 9); row = the range.
chan_1994/bands_chutjian_1972#
{
"id": "bands_chutjian_1972",
"material": "N2O",
"file": "N2O/chan_1994__bands_chutjian_1972.csv",
"table": "tbl_c3cbc336c3cb",
"quantity": "oscillator_strength",
"abscissa": "label",
"use": "reproduced",
"reproduced_from": [
"A. Chutjian and G. A. Segal, J. Chem. Phys. 57, 3069 (1972)"
]
}
Table 2: oscillator strengths of the B 1Delta, C 1Pi and D 1Sigma+ continuum bands below 10 eV (rows B, C, D; the source’s own integration ranges are not stated here); theory, semiempirical INDO (printed on the ‘theory’ row, the reference on the next); the D value is double the present one (p. 10).
chan_1994/bands_huebner_1975#
{
"id": "bands_huebner_1975",
"material": "N2O",
"file": "N2O/chan_1994__bands_huebner_1975.csv",
"table": "tbl_c3cbc336c3cb",
"quantity": "oscillator_strength",
"abscissa": "label",
"use": "reproduced",
"reproduced_from": [
"R. H. Huebner, R. J. Celotta, S. R. Mielczarek and C. E. Kuyatt, J. Chem. Phys. 63, 4490 (1975)"
]
}
Table 2: oscillator strengths of the B 1Delta, C 1Pi and D 1Sigma+ continuum bands below 10 eV (rows B, C, D; the source’s own integration ranges are not stated here); electron impact at 100 eV, normalised at 13.41 eV to Cook et al.’s optical value; C about 15 % above and D about 7 % below the present values (p. 10).
chan_1994/bands_rabalais_1971#
{
"id": "bands_rabalais_1971",
"material": "N2O",
"file": "N2O/chan_1994__bands_rabalais_1971.csv",
"table": "tbl_c3cbc336c3cb",
"quantity": "oscillator_strength",
"abscissa": "label",
"use": "reproduced",
"reproduced_from": [
"J. W. Rabalais, J. M. McDonald, V. Scherr and S. P. McGlynn, Chem. Rev. 71, 73 (1971)"
]
}
Table 2: oscillator strengths of the B 1Delta, C 1Pi and D 1Sigma+ continuum bands below 10 eV (rows B, C, D; the source’s own integration ranges are not stated here); photoabsorption; the C value 0.007 ‘is likely to be incorrect’ (their spectrum agrees with the present one, p. 9).
chan_1994/bands_zelikoff_1953#
{
"id": "bands_zelikoff_1953",
"material": "N2O",
"file": "N2O/chan_1994__bands_zelikoff_1953.csv",
"table": "tbl_c3cbc336c3cb",
"quantity": "oscillator_strength",
"abscissa": "label",
"use": "reproduced",
"reproduced_from": [
"zelikoff_1953"
]
}
Table 2: oscillator strengths of the B 1Delta, C 1Pi and D 1Sigma+ continuum bands below 10 eV (rows B, C, D; the source’s own integration ranges are not stated here); photoabsorption; the same values as zelikoff_1953’s continuum_f, whose own ranges (46000-65000, 64250-73000, 73000-82250 cm^-1) differ from this table’s header; agreement exact.
chan_1994/intervals_huebner_1975#
{
"id": "intervals_huebner_1975",
"material": "N2O",
"file": "N2O/chan_1994__intervals_huebner_1975.csv",
"table": "tbl_989c4d1b6636",
"quantity": "interval_oscillator_strength",
"abscissa_unit": "eV",
"columns": {
"x_upper": "eV"
},
"use": "reproduced",
"reproduced_from": [
"R. H. Huebner, R. J. Celotta, S. R. Mielczarek and C. E. Kuyatt, J. Chem. Phys. 63, 4490 (1975)"
]
}
Table 3 ‘ref. [33]’: Huebner et al.’s electron-impact integrated oscillator strengths ‘over the same energy intervals’, 10.23-13.95 eV (21 intervals); ‘in general about 10%-15% higher than the present results’, possibly from dipole-forbidden contributions at 100 eV impact energy (p. 11).
Formulas#
chan_1994/tail_fit#
{
"id": "tail_fit",
"material": "N2O",
"equation": "Section 3.1, p. 5",
"printed": "df/dE = A E^-2 + B E^-3 + C E^-4, fitted over 90-203 eV: 'A = 2.005, B = 150.9 and C = -652.3 (x10^4)'",
"variable": "E: photon energy in eV; df/dE (in Table 1's unit, 10^-2 eV^-1) = factor x (A E^-2 + B E^-3 + C E^-4), the printed '(x10^4)' read as applying to all three coefficients",
"state": "none (per molecule)",
"density": "none",
"range": "fitted over 90-203 eV; used to estimate the valence-shell oscillator strength above 203 eV (7.1 % of 16.51)",
"coefficients": {
"A": "2.005",
"B": "150.9",
"C": "-652.3",
"factor": "1e4"
},
"check": "With the factor on all three coefficients and df/dE in 10^-2 eV^-1: the integral from 203 eV to infinity is 1.1682, 7.08 % of 16.51 (printed 7.1 %); the curve gives 0.663 at 203.00 eV and 3.404 at 100.54 eV against Table 1's 0.686 and 3.44 (computed 2026-09-27)."
}
The paper’s high-energy extrapolation of the low-resolution df/dE (Fig. 1 insert, to 300 eV). As in chan_1993_co2’s tail_fit, the factor and the unit are inferred from the check; the coefficients are as printed.
Corrections#
[
{
"dataset": "continuum",
"row": "129.28",
"column": "x",
"printed": "129.28",
"corrected": "129.23",
"reason": "Table 1's energies above 80 eV step by 2.05 eV (121.03, 123.08, 125.13, 127.18, then 133.33, 135.38 ...); the printed 129.28 and 131.23 break the grid (steps 2.10, 1.95, 2.10) where 129.23 and 131.28 keep it. The carbon dioxide paper of the same series (chan_1993_co2, Table 1) prints the same grid with 129.23 and 131.28. Transposed last digits.",
"evidence": "Table image tbl_b536b17df805.jpg prints 129.28 and 131.23 in the fourth column pair (checked 2026-09-27); chan_1993_co2's tbl_b45cfc94562b.jpg prints 127.18, 129.23, 131.28, 133.33."
},
{
"dataset": "continuum",
"row": "131.23",
"column": "x",
"printed": "131.23",
"corrected": "131.28",
"reason": "Table 1's energies above 80 eV step by 2.05 eV (121.03, 123.08, 125.13, 127.18, then 133.33, 135.38 ...); the printed 129.28 and 131.23 break the grid (steps 2.10, 1.95, 2.10) where 129.23 and 131.28 keep it. The carbon dioxide paper of the same series (chan_1993_co2, Table 1) prints the same grid with 129.23 and 131.28. Transposed last digits.",
"evidence": "Table image tbl_b536b17df805.jpg prints 129.28 and 131.23 in the fourth column pair (checked 2026-09-27); chan_1993_co2's tbl_b45cfc94562b.jpg prints 127.18, 129.23, 131.28, 133.33."
}
]
Formula corrections, where recorded, appear with their formulas above. Curation notes may also discuss corrections or unresolved interpretation. Consult the review register for the checks and decisions.