Rydberg state
The Rydberg states[1] of an atom or molecule are electronically excited states with energies that follow the Rydberg formula as they converge on an ionic state with an ionization energy. Although the Rydberg formula was developed to describe atomic energy levels, it has been used to describe many other systems that have electronic structure roughly similar to atomic hydrogen.[2] In general, at sufficiently high principal quantum numbers, an excited electron-ionic core system will have the general character of a hydrogenic system and the energy levels will follow the Rydberg formula. Rydberg states have energies converging on the energy of the ion. The ionization energy threshold is the energy required to completely liberate an electron from the ionic core of an atom or molecule. In practice, a Rydberg wave packet is created by a laser pulse on a hydrogenic atom and thus populates a superposition of Rydberg states.[3] Modern investigations using pump-probe experiments show molecular pathways – e.g. dissociation of (NO)2 – via these special states.[4]
Rydberg series
Rydberg series describe the energy levels associated with partially removing an electron from the ionic core. Each Rydberg series converges on an ionization energy threshold associated with a particular ionic core configuration. These quantized Rydberg energy levels can be associated with the quasiclassical Bohr atomic picture. The closer you get to the ionization threshold energy, the higher the principal quantum number, and the smaller the energy difference between "near threshold Rydberg states." As the electron is promoted to higher energy levels, the spatial excursion of the electron from the ionic core increases and the system is more like the Bohr quasiclassical picture.
Energy of Rydberg states
The energy of Rydberg states can be refined by including a
Molecular Rydberg states
Although the energy formula of Rydberg series is a result of
See also
References
- ^ "Students create exotic state of matter". 15 November 2016.
- ISBN 9780750316354.
- PMID 15796697.
- S2CID 40024888.
- ^ Stohr, J., "NEXAFS Spectroscopy" Springer Series in Surface Science 25, (1992), p. 86.
- Atomic Spectra and Atomic Structure, Gerhard Herzberg, Prentice-Hall, 1937.
- Atoms and Molecules, Martin Karplus and Richard N. Porter, Benjamin & Company, Inc., 1970.
External links
- Army Creates Quantum Sensor That Detects Entire Radio-Frequency Spectrum; Defense One.
- Rydberg Atoms and the Quantum Defect; Physics Department, Davidson College.
- Rydberg Transitions; Chemistry and Biochemistiry, Georgia Tech.