energy hypersurface (potential energy surface) (PES)
The notion of hypersurface is used to stress the multidimensionality of PESs. In a molecular system consisting of \(N\) atomic nuclei, the number of the independent coordinates that fully determine the PES is equal to \(3\ N-6\) (or \(3\ N-5\) if the system is linear).
PAC, 1999, 71, 1919. (Glossary of terms used in theoretical organic chemistry) on page 1938 [Terms] [Paper]