A formalism is proposed for simulation of NOESY, ROESY, effective field at a well-defined angle from the longitudinal and, more specifically, off-resonance ROESY nuclear magnetic axis during the cross-relaxation mixing time. This angle can resonance spectra. The off-resonance ROESY experiment has sevbe manipulated by changing the magnitude and the freeral advantages compared to standard NOESY and ROESY experquency of the applied RF field. The experiment can be coniments. A simplified formalism which allows rapid computer simusidered a combination of the NOESY and ROESY experilation of the development of magnetization, including relaxation, ments because the observed auto-and cross-relaxation rates in the presence of an RF field is of general use, in particular in are linear combinations of longitudinal and transverse relaxthe implementation and interpretation of off-resonance ROESY experiments. The relevant matrix equations can be derived either ation rates (7, 8). The off-resonance ROESY experiment from the classical Bloch and Solomon equations or from the quanprovides the possibility of determining both longitudinal and tum mechanical homogeneous master equation in the basis of the transverse cross-relaxation rates with high accuracy. Thus it Cartesian product operators. Examples of simulated spectra and will, in principle, provide increased precision in distances behavior of magnetization during pulse sequences are shown. In used in structure determinations as well as information on addition, we present the full quantum mechanical theory for a dynamics (9). It has previously been shown for NOESY two-spin system derived from the homogeneous master equation.
data that a complete analysis of experimental data using the The proposed formalism, here applied to off-resonance ROESY, has many potential applications, e.g., in the development and anal-Solomon equations (10) will increase the precision of the ysis of ROESY and TOCSY mixing sequences, selective pulses, measured distances compared to the common isolated spin and decoupling in which the complete spin dynamics, including pair approximation (11, 12). Here, we present a similar prorelaxation, is taken into account. ᭧ 1997 Academic Press cedure useful for the analysis of off-resonance ROESY spectra and experiments. Simplified algorithms for the description of the off-resonance ROESY experiments have been