Ab initio Electronic Structure of Liquid Water

Area of Science:

• Condensed matter physics
• Quantum chemistry
• Materials science

Background:

• Accurate electronic structure determination is crucial for understanding material properties.
• Liquid water's electronic properties are complex and influenced by dynamic hydrogen bonding and quantum effects.

Purpose of the Study:

• To determine the electronic structure of liquid water using advanced computational methods.
• To quantify the impact of nuclear quantum effects and hydrogen-bond fluctuations on the band gap.
• To resolve ambiguities in the band-edge positions of liquid water.

Main Methods:

• Self-consistent GW calculations with vertex corrections for electronic structure.
• Ab initio path-integral molecular dynamics simulations to include nuclear quantum effects.

Main Results:

• A significant band-gap renormalization of up to 0.7 eV was observed due to hydrogen-bond quantum fluctuations.
• The calculated band gap of liquid water is 8.9 eV, consistent with experimental values.
• Valence-band maximum and conduction-band minimum were determined to be -9.4 eV and -0.5 eV, respectively, relative to the vacuum level.

Conclusions:

• Nuclear quantum effects and hydrogen bonding play a critical role in liquid water's electronic band gap.
• The study provides accurate electronic band-edge positions for liquid water, resolving previous discrepancies.