scholarly journals Complexes formed in collisions between ultracold alkali-metal diatomic molecules and atoms

2021 ◽  
Author(s):  
Matthew David Frye ◽  
Jeremy M Hutson
Keyword(s):  
Alkali Metal ◽  
Spin Exchange ◽  
Diatomic Molecules ◽  
Peak Height ◽  
Nuclear Spins ◽  
Vibrational States ◽  
Ultracold Collisions ◽  
Fermi Contact ◽  
Near Degeneracy ◽  
Fine And Hyperfine Structure

Abstract We explore the properties of 3-atom complexes of alkali-metal diatomic molecules with alkali-metal atoms, which may be formed in ultracold collisions. We estimate the densities of vibrational states at the energy of atom-diatom collisions, and find values ranging from 3.9 to 350 K$^{-1}$. However, this density does not account for electronic near-degeneracy or electron and nuclear spins. We consider the fine and hyperfine structure expected for such complexes. The Fermi contact interaction between electron and nuclear spins can cause spin exchange between atomic and molecular spins. It can drive inelastic collisions, with resonances of three distinct types, each with a characteristic width and peak height in the inelastic rate coefficient. Some of these resonances are broad enough to overlap and produce a background loss rate that is approximately proportional to the number of outgoing inelastic channels. Spin exchange can increase the density of states from which laser-induced loss may occur.

Polarization of the nuclear spins of noble-gas atoms by spin exchange with optically pumped alkali-metal atoms

1984 ◽  
Vol 29 (6) ◽  
pp. 3092-3110 ◽  
Author(s):  
W. Happer ◽  
E. Miron ◽  
S. Schaefer ◽  
D. Schreiber ◽  
W. A. van Wijngaarden ◽  
...  
Keyword(s):  
Alkali Metal ◽  
Spin Exchange ◽  
Noble Gas ◽  
Nuclear Spins ◽  
Optically Pumped ◽  
Metal Atoms

Transmission of Transverse Magnetization in Spin-Exchange Collisions of Alkali Metal Atoms

2018 ◽  
Vol 44 (10) ◽  
pp. 860-861 ◽  
Author(s):  
S. P. Dmitriev ◽  
N. A. Dovator ◽  
E. N. Pestov ◽  
V. A. Kartoshkin ◽  
A. I. Okunevich
Keyword(s):  
Alkali Metal ◽  
Spin Exchange ◽  
Transverse Magnetization ◽  
Metal Atoms

Localized spin orbital view of Fermi contact coupling of geminal nuclear spins

1973 ◽  
Vol 95 (24) ◽  
pp. 7956-7961 ◽  
Author(s):  
Keith F. Purcell ◽  
Richard L. Martin
Keyword(s):  
Nuclear Spins ◽  
Spin Orbital ◽  
Fermi Contact

scholarly journals Photolysis of diatomic molecules as a source of atoms in planetary exospheres

2020 ◽  
Vol 633 ◽  
pp. A39 ◽  
Author(s):  
R. R. Valiev ◽  
A. A. Berezhnoy ◽  
I. S. Gritsenko ◽  
B. S. Merzlikin ◽  
V. N. Cherepanov ◽  
...  
Keyword(s):  
Alkali Metal ◽  
Quantum Chemistry ◽  
Cross Sections ◽  
Diatomic Molecules ◽  
Astronomical Unit ◽  
Quiet Sun ◽  
Metal Atoms ◽  
The Cross ◽  
Planetary Exospheres

We calculated the cross sections of photolysis of OH, LiO, NaO, KO, HCl, LiCl, NaCl, KCl, HF, LiF, NaF, and KF molecules using quantum chemistry methods. The maximal values for photolysis cross sections of alkali metal monoxides are on the order of 10−18 cm2. The lifetimes of photolysis for quiet Sun at 1 astronomical unit are estimated as 2.0 × 105, 28, 5, 14, 2.1 × 105, 225, 42, 52, 2 × 106, 35 400, 486, and 30 400 s for OH, LiO, NaO, KO, HCl, LiCl, NaCl, KCl, HF, LiF, NaF, and KF, respectively. We performed a comparison between values of photolysis lifetimes obtained in this work and in previous studies. Based on such a comparison, our estimations of photolysis lifetimes of OH, HCl, and HF have an accuracy of about a factor of 2. We determined typical kinetic energies of main peaks of photolysis-generated metal atoms. Impact-produced LiO, NaO, KO, NaCl, and KCl molecules are destroyed in the lunar and Hermean exospheres almost completely during the first ballistic flight, while other considered molecules are more stable against destruction by photolysis.

scholarly journals Nuclear spin relaxation by intramolecular interactions in gases of homonuclear diatomic molecules

1976 ◽  
Vol 54 (22) ◽  
pp. 2209-2212 ◽  
Author(s):  
Myer Bloom ◽  
Peter Beckmann ◽  
B. C. Sanctuary
Keyword(s):  
High Temperatures ◽  
Spin Relaxation ◽  
Nuclear Spin ◽  
Diatomic Molecules ◽  
Intramolecular Interactions ◽  
Spin Density Matrix ◽  
Nuclear Spin Relaxation ◽  
Nuclear Spins ◽  
Rotational States ◽  
Homonuclear Diatomic Molecules

The differential equations which describe the relaxation of macroscopic observables associated with nuclear spins in homonuclear diatomic molecules are derived using an expansion of the nuclear spin density matrix in terms of irreducible tensors. It is shown, using an intramolecular quadrupole mechanism, that the only difference between nuclear spin relaxation of the ortho- and para-species arises from the rotational states being restricted to odd and even values. This difference is vanishingly small at high temperatures so that the relaxation equations for nuclear magnetization become identical for both species. A previous paper predicting a difference even at high temperatures is shown to be in error and is corrected.

scholarly journals About the Dunham coefficients Y20 and Y11 for diatomic molecules

2001 ◽  
Vol 79 (9) ◽  
pp. 1169-1173
Author(s):  
A K Sharma ◽  
S Chandra
Keyword(s):  
Potential Energy ◽  
Diatomic Molecule ◽  
Potential Energy Curve ◽  
Diatomic Molecules ◽  
Turning Points ◽  
Energy Curve ◽  
Vibrational States

For a diatomic molecule, when the Dunham coefficient Y20 is negative, all features of the potential-energy curve can be reproduced. When Y20 is positive, it is not possible to reproduce all features of the potential-energy curve. However, the turning points for some lower vibrational states can be obtained. PACS No.: 33.15Mt

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