saenz_2000
==========

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

`Source record <https://github.com/LupoLab/optmat/blob/main/src/optmat/data/sources/saenz_2000.toml>`__ · :doc:`Catalogue </the-data/sources>` · :doc:`Review register </register>`

DOI: `10\.1103/PhysRevA\.61\.051402 <https://doi.org/10.1103/PhysRevA.61.051402>`__

**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
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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
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No datasets are recorded.

Formulas
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No formulas are recorded.

Corrections
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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 :doc:`review register </register>` for the checks and decisions.