Atomic negative ion

Esaulov A V 1986 Electron detachment from atomic negative ions Ann. Phys., Pahs 11 493-592... 

Hotop, H. and Lineberger, W.C. (1975) Binding energies in atomic negative ions. II. Journal of Physical and Chemical Reference Data, 14, 731—750. 

Holoien and Geltman also have found that the ls 2p state of He is bound with respect to the Is 2p P° state of He the electron affinity of this state is calculated to be > 0.20 eV. This state is metastable against autodetachment via the Coulomb interaction. Holoien and Geltman indicate its lifetime against autodetachment to be of the same order as that for the P state and that it may radiate to the metastable P° state. The extent of contributions of the P° and P metastable states to the observed He ion beams is presently unknown. Buchel nikova Smir-nov and Masseyhave summarized much of the present knowledge of atomic negative ions. 

A comparison of the isoelectronlc sequence - H (g), He(g), Li (g) - would suggest that stable electronic states may exist at 0,8 EA(H) or roughly 6400 cm . This would greatly affect the entropy. However, Pekeris (4) states that he was unable to find any bound states. In addition, Seman and Branscomb (1 ) state that theoretical and semiemplrical evidence suggests that atomic negative ions have very few if any excited states below the continuum. We assume no stable excited states exist. 

There are only few rigorous results on critical phenomena for many-body systems, and most of them are variational bounds. As an example, for iV-electron atoms, experimental results [61] and numerical calculations [62] rule out the stability of doubly charged atomic negative ions in the gas phase. However, a rigorous proof exists only for the instability of doubly charged hydrogen negative ions [63]. 

S.J. Buckman, C.W. Qark, Atomic negative-ion resonances. Rev. Mod. Phys. 66 (1994) 539. [51 ] Ph. Durand, 1. Paidarova, Modeling quantum resonances 11. Overview of collision theory, in J. Maruani, R. Lefebvre, E. Brandas (Eds.), Advanced Topics in Theoretical Chemical Physics, Vol. 12 Progress in Theoretical Chemishy and Physics, Kluwer Academic, Dordrecht, 2003, p. 295... 

T. Andersen, Atomic negative ions Structure, dynamics and collisions, Phys. Rep. 394 (2004) 157. 

N. A. Piangos, C.A. Nicolaides, Very highly excited bound states of atomic negative ions having aU their electrons with unpaired spins, J. Phys. B 31 (1998) L147. 

Recently, the technique has been applied successufully to the determination of the electron affinities of a series of molecules. Ion-pair formation (Section 3.4) at threshold was used to prepare atomic negative ions of the halogen, free of electrons and with thermal kinetic energy. These ions were carefully accelerated in a double-chamber ion source [Fig. 1(c)] which also contained the reactant gas, and the thresholds were... 

Hotop, W., Linebeiger, W. C. (1985). Binding energies in atomic negative ions. H. J. Phys. Chem. Ref. Data 14, 731-750. 

Prasad M, Sen KD (1991) Upper bound to approximate ionic radii of atomic negative ions in terms of r. J Chem Phys 95 1421-1422... 

Positive ions are much smaller than their atoms. Negative ions are slightly larger than their atoms. 

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