Residual chemical shift anisotropy

Residual chemical shift anisotropy (RCSA) refers to a phenomenon observed primarily in the context of nuclear magnetic resonance (NMR) spectroscopy, particularly in solid-state NMR and biomolecular NMR. It is an important concept in understanding how molecular dynamics and interactions affect chemical shifts of nuclei in a sample. In NMR, chemical shifts arise from the magnetic environments surrounding nuclei, which can be influenced by the electronic environment created by nearby atoms and molecular structure.