Open AccessThe life of π and σ—A tutorial review of the ubiquitous use of these symbols in Zeeman and magnetic‐resonance spectroscopy
Author(s) -
Weil John Ashley
Publication year - 2008
Publication title -
concepts in magnetic resonance part a
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.229
H-Index - 49
eISSN - 1552-5023
pISSN - 1546-6086
DOI - 10.1002/cmr.a.20105
Subject(s) - zeeman effect , spectroscopy , polarization (electrochemistry) , electron paramagnetic resonance , photon , nuclear magnetic resonance spectroscopy , nuclear magnetic resonance , resonance (particle physics) , physics , atomic physics , theoretical physics , chemistry , quantum mechanics , magnetic field
Certain concepts and symbolism as applied to electromagnetic radiation and especially the concept of photons are discussed and (perhaps) clarified. A useful summary of the properties of photons is provided, and the concept of polarization is discussed. In particular, the common usage in Zeeman and magnetic‐resonance (EPR and NMR) spectroscopy of the symbols π and σ is examined herein, both from the historical viewpoint and the scientific standpoint, and certain errors and fallacies are brought to attention. Brief reference to relevant recent work published on dynamic nuclear polarization and on pulse EPR is included. © 2008 Wiley Periodicals, Inc.Concepts Magn Reson Part A 32A: 134–142, 2008.