Carbon-13 nuclear magnetic resonance (most commonly known as carbon-13 NMR or ¹³C NMR or sometimes simply referred to as carbon NMR) is the application of nuclear magnetic resonance (NMR) spectroscopy to carbon. It is analogous to proton NMR ( NMR) and allows the identification of carbon atoms in an organic molecule just as proton NMR identifies hydrogen atoms. As such ¹³C NMR is an important tool in chemical structure elucidation in organic chemistry. ¹³C NMR detects only the  isotope of carbon, whose natural abundance is only 1.1%, because the main carbon isotope, , is not detectable by NMR since it has zero net spin.