How flexible is the water molecule structure? Analysis of crystal structures and the potential energy surface

Abstract

Water molecules from crystal structures archived in the CSD show a relatively large range both in the bond angle and bond lengths. High level ab initio calculations at the CCSD(T)/CBS level predicted a possibility for energetically low-cost (±1 kcal mol⁻¹) changes of the bond angle and bond lengths in a wide range, from 96.4° to 112.8° and from 0.930 Å to 0.989 Å, respectively.