Exploring electric field induced structural evolution of water clusters, (H2O)n [n = 9-20]: density functional...

Area of Science:

• Computational chemistry
• Physical chemistry
• Materials science

Background:

• Neutral water clusters exhibit complex hydrogen-bond networks.
• Understanding cluster response to external fields is crucial for molecular dynamics.

Purpose of the Study:

• Investigate the structural and electronic response of neutral water clusters (n=9-20) to static electric fields.
• Characterize field-induced conformational transitions and their impact on cluster properties.

Main Methods:

• Density Functional Theory (DFT) computations using B3LYP/6-311++G(2d,2p) model chemistry.
• Analysis of lowest-energy conformers within a specific energy range.

Main Results:

• Increasing electric fields weaken hydrogen bonds, leading to structural distortion and breakdown.
• Field-induced transitions to extended, low-energy configurations along the field direction were observed.
• Structural transitions are accompanied by abrupt increases in electric dipole moment and a decrease in the HOMO-LUMO energy gap, approaching zero at breakdown.
• Clusters transform into net-like structures with fewer hydrogen bonds, indicating increased complexity.

Conclusions:

• Static electric fields significantly alter water cluster structures and electronic properties.
• The observed transitions and breakdown phenomena highlight the sensitivity of hydrogen-bond networks to external fields.
• These findings provide insights into the behavior of larger water clusters and their potential for novel structural motifs.