title: Electric field effects on the intermolecular interactions in water whiskers: insight from structures, energetics, and properties.
abstract: Modulation of intermolecular interactions in response to external electric fields could be fundamental to the formation of unusual forms of water, such as water whiskers. However, a detailed understanding of the nature of intermolecular interactions in such systems is lacking. In this paper, we present novel theoretical results based on electron correlation calculations regarding the nature of H-bonds in water whiskers, which is revealed by studying their evolution under external electric fields with various field strengths. We find that the water whiskers consisting of 2-7 water molecules all have a chain-length dependent critical electric field. Under the critical electric field, the most compact chain structures are obtained, featuring very strong H-bonds, herein referred to as covalent H-bonds. In the case of a water dimer whisker, the bond length of the novel covalent H-bond shortens by 25%, the covalent bond order increases by 9 times, and accordingly the H-bond energy is strengthened by 5 times compared to the normal H-bond in a (H2O)2 cluster. Below the critical electric field, it is observed that, with increasing field strength, H-bonding orbitals display gradual evolutions in the orbital energy, orbital ordering, and orbital nature (i.e., from typical π-style orbital to unusual σ-style double H-bonding orbital). We also show that, beyond the critical electric field, a single water whisker may disintegrate to form a loosely bound zwitterionic chain due to a relay-style proton transfer, whereas two water whiskers may undergo intermolecular cross-linking to form a quasi-two-dimensional water network. Overall, these results help shed new insight on the effects of electric fields on water whisker formation.
authors.affiliation: State Key Laboratory of Theoretical and Computational Chemistry Institute of Theoretical Chemistry, Jilin University , Changchun 130023, P. R. China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Bai
authors.forename: Hui-Min
authors.initials: HM
authors.lastname: He
authors.forename: Ying
authors.initials: Y
authors.lastname: Li
authors.forename: Zhi-Ru
authors.initials: ZR
authors.lastname: Li
authors.forename: Zhong-Jun
authors.initials: ZJ
authors.lastname: Zhou
authors.forename: Jia-Jun
authors.initials: JJ
authors.lastname: Wang
authors.forename: Di
authors.initials: D
authors.lastname: Wu
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.forename: Feng-Long
authors.initials: FL
authors.lastname: Gu
authors.forename: Bobby G
authors.initials: BG
authors.lastname: Sumpter
authors.forename: Jingsong
authors.initials: J
authors.lastname: Huang