Molecular Rydberg states in hydrogen negative ion discharges

1996 ◽  
Vol 69 (6) ◽  
pp. 755-757 ◽  
Author(s):  
J. R. Hiskes
Keyword(s):  
1985 ◽  
Vol 63 (8) ◽  
pp. 1015-1021 ◽  
Author(s):  
Paul Marmet ◽  
Hamid K. Nasrallah

Electroionization spectra of HBr and DBr are measured and analyzed between the ionization threshold and 25 eV. Several negative-ion states having configurations (4pσ) (4pπ)4 5s2, 5p2, and 4d2, associated with Rydberg states converging to the 2Σ+ limit, have been identified. Other structures result from the excitation of the inner 4sσ electron. Finally, data on DBr are used to confirm the interpretation.


2008 ◽  
Vol 6 (1) ◽  
pp. 77-88
Author(s):  
Bogdan Ibanescu ◽  
Michael Allan

A dramatic difference was observed in the reactivity of alcohols and ethers toward free electrons. Whereas the lowest core-excited state of the negative ion - a 2(n,3s2) Feshbach resonance - of the alcohols readily dissociates by losing a hydrogen atom, ethers show no observable signal from this resonance. This difference in reactivity has a parallel in the anomalous shapes and energies of the parent states of the Feshbach resonances, the 1(n,3s) Rydberg states of the neutral alcohols and ethers. We explained this anomaly by means of potential surfaces of the alcohols and ethers calculated using the TD-DFT method as a function of the dissociation coordinate. The lowest excited state of alcohols was found to be repulsive, as a consequence of an avoided crossing between the 3s and 3px Rydberg configurations, whereas a barrier to dissociation was found in the ethers. Rydberg-valence mixing and avoided crossings are decisive in determining the shapes of the potential surfaces. It is concluded that the reactivities of alcohols and ethers toward free electrons are rationalized by assuming that the potential surfaces of the daughter Feshbach resonances closely follow those of the parent Rydberg states, i.e., the lowest Feshbach resonance is repulsive, but a barrier occurs in ethers. The potential surfaces of both the Rydberg states and the Feshbach resonances thus differ dramatically from the non-dissociative surface of the grandparent 2(n-1) positive ions, despite the nominally non-bonding character of the Rydberg electrons.


1974 ◽  
Vol 52 (19) ◽  
pp. 1885-1890 ◽  
Author(s):  
R. Carbonneau ◽  
P. Marmet

Negative ion resonances having the NO+b3Π, A1Π, c3Π, and B1Π states as grandparents are observed for the first time in the electroionization spectrum of NO. Our results are compared with those from electron transmission experiments. Moreover, some Rydberg states from the series converging to the NO+b3Π state have been analyzed.


1973 ◽  
Vol 51 (20) ◽  
pp. 2202-2208 ◽  
Author(s):  
R. Carbonneau ◽  
P. Marmet

Negative ion resonances and neutral Rydberg states having the A2Π and B2Σ+ states of CO+ as limits are reported for the first time in the electroionization curve of CO. Moreover, new doubly excited states of CO are observed around 21 eV. The electroionization is compared with photoionization, photoabsorption, and electron transmission when data are available.


2000 ◽  
Vol 98 (12) ◽  
pp. 793-806 ◽  
Author(s):  
Ian C. Lane, Andrew J. Orr-Ewing
Keyword(s):  

Sign in / Sign up

Export Citation Format

Share Document