yuen_2022#
C. H. Yuen and C. D. Lin, “Density-matrix approach for sequential dissociative double ionization of molecules”, Phys. Rev. A 106, 023120 (2022)
Source record · Catalogue · Review register
DOI: 10.1103/PhysRevA.106.023120
Source kind: theory
Recorded technique: Density-matrix model of sequential double ionisation (DM-SDI), Eqs. (1): the neutral, the cation and the dication are separate open systems. The neutral population decays by rate equations into the N2+ X 2Sigma_g+, A 2Pi_u and B 2Sigma_u+ states (ionisation of the HOMO 3sigma_g, HOMO-1 1pi_u and HOMO-2 2sigma_u); the three cation states are coupled by the field through the von Neumann equation with a source term; the cation states ionise by rate equations into the eleven N2^2+ states with two valence holes (Table I), which are not coupled to each other. All rates are MO-ADK (Tong et al. 2002), with the structure parameters of N2 from Zhao et al. 2010 (zhao_2010) for the neutral and the same parameters for the cation’s orbitals; the second ionisation energy is Table I’s I_p minus the cation state’s ionisation energy. Nuclei fixed at the neutral’s equilibrium, R = 1.09 angstrom (p. 3); no coherence between charge states or between states populated by tunnelling. Solved by the classic Runge-Kutta method, averaged over isotropic alignment (Eq. 2) and convolved with a Gaussian of sigma = 0.28 eV for the KER spectrum (Eq. 3).
Materials in structured entries: N2, N2+
Dataset quantities: ionization_energy, kinetic_energy_release, transition_dipole_moment
Contents: 6 datasets; 0 formulas.
Curation notes#
The library holds the accepted manuscript (CHORUS, 11 PDF pages; dated 23 August 2022, published 31 August 2022); pages are cited as PDF pages. Identity checked on PDF pp. 1-2 (C. H. Yuen and C. D. Lin, J. R. Macdonald Laboratory, Kansas State University) on 2026-10-09. The register entry is TC-955.
THE PULSE OF THE MODEL (p. 4): E(t) = E0 exp(-2 ln 2 t^2 / Gamma^2) cos(omega t), Gamma the intensity FWHM, fixed at 8 fs throughout (‘a longer pulse would allow the nuclei to move appreciably’); linear polarisation in the xz plane, the molecular axis along z. Main results (Figs. 2, 3, 6-8): 800 nm, 1.2e15 W/cm^2 peak, to compare with Voss et al. 2004 (800 nm, 8 fs, 1.2e15 W/cm^2). Fig. 4 also 391 and 918 nm; Fig. 5 the intensity dependence; Fig. 7 a Gaussian-beam volume average (Eq. 4). ‘the ratio between the 1st to 2nd peak in the spectrum changes by at most 2% and 1% for different pulse durations (5 - 8 fs) and carrier-envelop phases (0 - pi)’ (p. 7).
TABLE I (p. 5): taken. I_p ‘taken from Bhattacharya et al [28]’ (J. Phys. Chem. A 125, 7778 (2021)), measured from the neutral N2 ground state (‘Vertical ionization energy to the N2^2+ states’); limits ‘taken from Iwayama et al [25]’ (J. Chem. Phys. 145, 034305 (2016)), those of states 10 and 11 ‘identified from the PEC’ of ref. 28; KER the model’s. The limits are named, not given as energies: I_p - KER is 38.96 eV for every 3P + 3P row and 42.76 eV for both 1D + 1D rows (checked by the script), so no dissociation_energy dataset is made. State 10 is printed ‘m.s. / N+(1D) + N+(1D)’ with a KER of 7.81 eV; it is put with the 1D + 1D limit. The text names the KER peaks of the spectrum: 6.77 eV (mostly state 5), 7.58 eV (states 6-8), 10.16 eV (state 9) (p. 6).
TEXT VALUES (taken as points): the ‘experimental ionization energy of 15.58, 16.93, and 18.75 eV for HOMO, HOMO-1, and HOMO-2’ (p. 4), no reference given; the dipole couplings of the cation, ‘d_x = 0.25 a0 [29]’ between X and A and ‘d_z = 0.75 a0 [30]’ between X and B (p. 3; refs. 29-30 Langhoff, Bauschlicher and Partridge 1987, Langhoff and Bauschlicher 1988). Also on p. 4, not taken (they are Table I’s differences): ‘The ionization energy to state 6 from the A and from the B state are then 29.49 and 27.67 eV’ = 46.42 - 16.93 and 46.42 - 18.75.
THE STRUCTURE PARAMETERS are not printed: the paper uses zhao_2010’s for N2 and the same for the cation.
NO COUPLINGS BETWEEN DICATION STATES in this model; Jia et al. 2024 (jia_2024) add them and the vibrational spread of R.
FIGURES (not digitised; vector drawings except Fig. 1): Fig. 2 bottom, the angle-averaged yields of the dissociative N2^2+ states 5-11 with and without the cation couplings (800 nm, 8 fs, 1.2e15 W/cm^2), the populations of the dication left by the pulse; Fig. 5, the angle-averaged yield of states 1-9 against peak intensity; Fig. 3, the X, A, B populations against time at 45 degrees; Figs. 2 top, 4, 6-8, KER spectra (wavelength, volume and alignment). Fig. 1 (potential curves, from ref. 28) is a raster image.
Recorded bibliographic identity status: VALIDATED. This concerns identification of the source; it does not establish the scientific correctness of its contents.
Datasets#
yuen_2022/table1_ip#
{
"id": "table1_ip",
"material": "N2",
"file": "N2/yuen_2022__table1_ip_N2.csv",
"table": "tbl_076ba83089ee",
"quantity": "ionization_energy",
"unit": "eV",
"abscissa": "label",
"use": "reproduced",
"reproduced_from": [
"D. Bhattacharya, K. R. Shamasundar and A. Emmanouilidou, J. Phys. Chem. A 125, 7778 (2021)"
],
"parameters": {
"kind": "vertical",
"initial_state": "N2 X 1Sigma_g+",
"final_state": "the N2^2+ state of the row"
}
}
Table I, ‘I_p (eV)’: the vertical double-ionisation energy from the neutral ground state to each N2^2+ state with two valence holes, at the neutral’s equilibrium geometry (R = 1.09 angstrom, p. 3); rows are the table’s index (states 1-11, used throughout the paper), x the state; the configuration is in the printed cells. States 1-4 are metastable. No uncertainty is stated.
yuen_2022/table1_ker_3p3p#
{
"id": "table1_ker_3p3p",
"material": "N2",
"file": "N2/yuen_2022__table1_ker_3p3p_N2.csv",
"table": "tbl_076ba83089ee",
"quantity": "kinetic_energy_release",
"unit": "eV",
"abscissa": "label",
"use": "check",
"parameters": {
"channel": "N2 -> N2^2+ (the state of the row) -> N+(3P) + N+(3P)",
"kind": "calculated",
"state": "the N2^2+ state of the row"
}
}
Table I, ‘KER (eV)’ of states 5-9 (rows: the table’s index), which dissociate to N+(3P) + N+(3P) (limit from Iwayama et al. 2016). The KER is the model’s: I_p of the row less the limit, 38.96 eV above the neutral as implied by every row (the limit’s energy is not printed). Vertical at R = 1.09 angstrom; the KER of a dication channel is filed under the neutral, N2, with the dication state in the channel (TC-954).
yuen_2022/table1_ker_1d1d#
{
"id": "table1_ker_1d1d",
"material": "N2",
"file": "N2/yuen_2022__table1_ker_1d1d_N2.csv",
"table": "tbl_076ba83089ee",
"quantity": "kinetic_energy_release",
"unit": "eV",
"abscissa": "label",
"use": "check",
"parameters": {
"channel": "N2 -> N2^2+ (the state of the row) -> N+(1D) + N+(1D)",
"kind": "calculated",
"state": "the N2^2+ state of the row"
}
}
Table I, ‘KER (eV)’ of states 10 (printed ‘m.s. / N+(1D) + N+(1D)’) and 11, whose limit N+(1D) + N+(1D) was ‘identified from the PEC from Ref. [28]’. I_p less KER is 42.76 eV for both. As table1_ker_3p3p otherwise.
yuen_2022/text_ip#
{
"id": "text_ip",
"material": "N2",
"table": "text",
"quantity": "ionization_energy",
"unit": "eV",
"abscissa": "label",
"use": "check",
"parameters": {
"kind": "not stated",
"initial_state": "N2 X 1Sigma_g+",
"final_state": "the N2+ state of the row"
}
}
3 inline points in the source record.
p. 4: ‘experimental ionization energy of 15.58, 16.93, and 18.75 eV for HOMO, HOMO-1, and HOMO-2 were used’ for the first ionisation, with no reference and no statement of vertical or adiabatic; the inputs of the model’s MO-ADK rates to the X, A and B states. zhao_2010’s Table IV prints 15.6, 17.2 and 18.7 eV as the experimental vertical values for the same orbitals.
yuen_2022/text_dipole_xa#
{
"id": "text_dipole_xa",
"material": "N2+",
"table": "text",
"quantity": "transition_dipole_moment",
"unit": "au",
"abscissa": "label",
"use": "reproduced",
"reproduced_from": [
"S. R. Langhoff, C. W. Bauschlicher Jr. and H. Partridge, J. Chem. Phys. 87, 4716 (1987)"
],
"parameters": {
"states": "X 2Sigma_g+ - A 2Pi_u",
"component": "perpendicular (x)",
"geometry": "the neutral's equilibrium, R = 1.09 angstrom"
}
}
1 inline points in the source record.
p. 3: ‘The X and A state ... are coupled by a dipole moment of d_x = 0.25 a0 [29]’; the model’s coupling at the neutral’s equilibrium geometry. jia_2024’s Table III (the same reference) gives 0.271 at R = 2.00 a0 and 0.262 at 2.10 a0, so about 0.265 at 1.09 angstrom (2.06 a0).
yuen_2022/text_dipole_xb#
{
"id": "text_dipole_xb",
"material": "N2+",
"table": "text",
"quantity": "transition_dipole_moment",
"unit": "au",
"abscissa": "label",
"use": "reproduced",
"reproduced_from": [
"S. R. Langhoff and C. W. Bauschlicher Jr., J. Chem. Phys. 88, 329 (1988)"
],
"parameters": {
"states": "X 2Sigma_g+ - B 2Sigma_u+",
"component": "parallel (z)",
"geometry": "the neutral's equilibrium, R = 1.09 angstrom"
}
}
1 inline points in the source record.
p. 3: ‘the X and B state are coupled by a dipole moment of ... d_z = 0.75 a0 [30]’; the model’s coupling at the neutral’s equilibrium geometry. jia_2024’s Table III (the same reference) gives 0.764 at R = 2.00 a0 and 0.729 at 2.10 a0, so about 0.74 at 1.09 angstrom (2.06 a0).
Formulas#
No formulas are recorded.
Corrections#
No dataset errata are recorded in this source record.
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.