A type of spectroscopy used in nuclear magnetic resonance (NMR) in which the pulse sequence used is: 90°x – t1 – 90°x – acquire (t2). The delay t1 is variable and a series of acquisitions is made. Fourier transforms are then performed on both the delay t1 and the real time t2. The information thus gained can be shown on a diagram that plots contours of signal intensity. This representation of the information enables NMR spectra to be interpreted more readily than in one-dimensional NMR, particularly for complex spectra.