“…To understand the interactions of biologically interesting molecules, it is necessary to know the shape of the interaction sites as well as the conformations of the interacting molecules and, the conformational analysis of Ach has been subject of many experimental 6–25 and theoretical 26–46 investigations. Aspects of the Ach potential energy surface (PES) have been the subject of numerous experimental investigations including X‐Ray 6–8, 16–21, NMR 9, 11–14, 23, 25, electron diffraction 22, and Raman Spectroscopy 15, in addition, computational studies have employed ab initio 3, 31, 34, 35, 42–44, semi empirical and empirical methods 26–30, 38, 39 as well as molecular dynamics 36, 37, 45.…”