Abstract
This introductory chapter recapitulates the basic concepts of nuclear magnetic relaxation. This includes the elementary physics of spins. Based on the Bloch equation for the time evolution of magnetizations, transverse and longitudinal spin relaxation times (or rates) are defined. As far as relaxation processes in general are concerned, the Wiener/Khinchin theorem plays a central role. It relates two crucial functions, namely autocorrelation functions and spectral densities. These are the information carriers of molecular dynamics, in the sense that they reflect the characteristics of the fluctuations of the spin interactions due to thermal motions.
Publisher
Royal Society of Chemistry