https://doi.org/10.1351/goldbook.E01986
If \(P(x,\,y,\,z)\ \text{d}x\ \text{d}y\ \text{d}z\) is the @P04855@ of finding an electron in the volume element \(\text{d}x\ \text{d}y\ \text{d}z\) at the point of a molecular entity with coordinates \(x,\,y,\,z\), then \(P(x,\,y,\,z)\) is the electron density at this point. For many purposes (e.g. X-ray @S05487@, forces on atoms) the system behaves exactly as if the electrons were spread out into a continuously distributed charge. The term has frequently been wrongly applied to negative @C00997@.
See also:
charge density