saenz_2000#

A. Saenz, “Enhanced ionization of molecular hydrogen in very strong fields”, Phys. Rev. A 61, 051402(R) (2000)

Source record · Catalogue · Review register

Source kind: theory

Recorded technique: Fully correlated three-dimensional ab initio calculation of H2 in a static field parallel to the molecular axis, within the Born-Oppenheimer approximation (fixed nuclei): the complete nonrelativistic Hamiltonian diagonalised in explicitly correlated two-electron functions in prolate spheroidal coordinates (Kolos’s code, extended for the field), with complex scaling for the autoionising (field-ionising) states; three 400-term basis sets, stable in overlapping ranges of R. The diagonalisation gives the adiabatic potential curves and ionisation rates directly (pp. 051402-1 and -2).

Materials in structured entries: None recorded.

Dataset quantities: None recorded.

Contents: 0 datasets; 0 formulas.

Curation notes#

Journal pp. 051402-1 to -4 = PDF pages 1-4. Identity checked on the first page. The paper is a Rapid Communication; the library copy has no extracted tables, and the pages hold none.

NOTHING IS TAKEN: the paper prints no rate. The ionisation rates of the H2 ground state are in figures only: Fig. 2(b), the adiabatic rates of the ground and first excited state against R at F = 0.06 au; Fig. 3, the adiabatic (a) and diabatic (b) ground-state rates against R (0-10 a0) for F = 0.053 38, 0.06, 0.08, 0.10 and 0.12 au, in units of 1e15 s^-1 on a log scale (1e-5 to 10); Fig. 4, the diabatic rate at F = 0.053 38 au against a one-dimensional model (Yu, Zuo & Bandrauk 1996). The rate at the equilibrium distance (R = 1.4 a0) is therefore not printed. Fig. 1: the adiabatic ground-state potential curves at F = 0.18, 0.12, 0.10, 0.08 and 0.053 38 au with the field-free curve and the classical dipole lines E = -FR + c. 1 au of field = 5.14e11 V/m (p. 051402-2).

WHAT THE RATE COUNTS: the width of the complex-scaled two-electron state, i.e. the ionisation rate of the whole molecule (both electrons), at fixed R, with the field along the axis. No convergence figure is given for the rates: the field-free ground state ‘agrees with the most accurate one within 1e-5 eV. This does, of course, not guarantee the same accuracy for the results obtained for H2 in an external field’; the ‘important features ... were all reproduced with any of the basis sets adopted. In fact, in most cases even the quantitative agreement was very good’ (p. 051402-2). ‘The minor peak on the shoulder [of Fig. 4] is only due to numerical inaccuracies’ (p. 051402-4).

R-DEPENDENCE (the finding; pp. 051402-2 to -4): an avoided crossing between the ground state and the lowest excited state (the ionic H+ H- state, whose energy falls as -FR) occurs near R ~ 5.3 a0 at F = 0.06 au. In the adiabatic limit the rate shows no peak (for weak fields a step); in the diabatic limit it peaks (‘enhanced ionization’) at an R that decreases with increasing F (Fig. 3(b)); no second crossing for R <= 10 a0. The 1D model’s peak is broader and double. This explains why R_max F is about constant for H2+ (Barnett & Gibson 1999). The rates in low-frequency fields and their comparison with ADK are left to ‘a forthcoming publication’ (saenz_2002).

REPRINTS: majety_2015’s Table 2 column [18] (majety_2015/table2_parallel_saenz_2000_H2: F = 0.06-0.12 au, R = 1.4 au, 3.36e-5 ... 1.29e-2 au) is attributed to this paper, but these numbers are not printed here (3.36e-5 au = 1.39e12 s^-1 at 0.06 au is of the magnitude Fig. 3 shows at R = 1.4 a0), so Majety & Scrinzi must have them from the figure or from the author. The re-point cannot be checked value by value.

Recorded bibliographic identity status: VALIDATED_WITH_WARNINGS. This concerns identification of the source; it does not establish the scientific correctness of its contents.

Datasets#

No datasets are recorded.

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.