Computer simulations of multiple-quantum NMR experiments. I. Nonselective excitation
The multiple-quantum (MQ evolution of anisotropic spin systems with four to eight coupled protons is analyzed using a computer for the basic three-pulse sequence. MQ intensities are first investigated as a function of preparation time. The concept of time-independent intensities is then introduced, and an algorithm for efficient computation of these quantities is described. A correlation between the distribution of dipolar coupling values and the intensity of high-quantum lines is discussed; in many cases, these intensities are predicted to be considerably larger than a simple statistical argument would suggest. The effect of varying the preparation and detection times independently is analyzed as a random walk problem. © 1984.