Abstract: A new method is proposed to determine internuclear distances from a 2D NOESY peak intensity or mixing coefficient matrix with a single mixing time. This method is carried out at two stages. At the first stage the symmetrized matrix of nuclear cross relaxation rate is obtained from the regularized 2D NOESY peak intensity or symmetrized mixing coefficient matrix. The calculation in the procedure is quite simple and general. At the second stage the internuclear distances can be extracted directly from the symmetrized nuclear cross relaxation rates and in the course of internuclear distance calculation the internal motion of molecules has been considered. This new method is self-consistent and internuclear distances in spin systems can be determined solely from a 2D NOESY peak intensity or mixing coefficient matrix with a single mixing time.

Key words: 2D NEOSY peak intensity, 2D NOESY mixing coefficient, Nuclear cross relaxation rate, Internuclear distance