Density Matrix Description of Nuclear Magnetic Double Resonance

Abstract

Bloch has given a general density matrix description of the nuclear magnetic double‐resonance problem. However, this formalism has not been widely applied to problems of chemical interest because of the generally intractable form of the equations and notation that arise for even the simplest spin systems. The use of the Redfield equation introduces significant simplifications into the treatment so that the density matrix description can be given in a form that is convenient for digital computation. An example of the density matrix description of the double‐resonance spectrum of a single nucleus of spin ½ is given in detail, and compared with frequency‐sweep double‐resonance spectra observed for the proton in CCl₃H.