TY  - JOUR
A1  - Pietzsch, Annette
A1  - Niskanen, Johannes
A1  - Vaz da Cruz, Vinicius
A1  - Büchner, Robby
A1  - Eckert, Sebastian
A1  - Fondell, Mattis
A1  - Jay, Raphael Martin
A1  - Lu, Xingye
A1  - McNally, Daniel
A1  - Schmitt, Thorsten
A1  - Föhlisch, Alexander
T1  - Cuts through the manifold of molecular H2O potential energy surfaces in liquid water at ambient conditions
JF  - Proceedings of the National Academy of Sciences of the United States of America
N2  - The fluctuating hydrogen bridge bonded network of liquid water at ambient conditions entails a varied ensemble of the underlying constituting H2O molecular moieties. This is mirrored in a manifold of the H2O molecular potentials. Subnatural line width resonant inelastic X-ray scattering allowed us to quantify the manifold of molecular potential energy surfaces along the H2O symmetric normal mode and the local asymmetric O-H bond coordinate up to 1 and 1.5 angstrom, respectively. The comparison of the single H2O molecular potentials and spectroscopic signatures with the ambient conditions liquid phase H2O molecular potentials is done on various levels. In the gas phase, first principles, Morse potentials, and stepwise harmonic potential reconstruction have been employed and benchmarked. In the liquid phase the determination of the potential energy manifold along the local asymmetric O-H bond coordinate from resonant inelastic X-ray scattering via the bound state oxygen ls to 4a(1) resonance is treated within these frameworks. The potential energy surface manifold along the symmetric stretch from resonant inelastic X-ray scattering via the oxygen 1 s to 2b(2) resonance is based on stepwise harmonic reconstruction. We find in liquid water at ambient conditions H2O molecular potentials ranging from the weak interaction limit to strongly distorted potentials which are put into perspective to established parameters, i.e., intermolecular O-H, H-H, and O-O correlation lengths from neutron scattering.
KW  - water
KW  - potential ene rgy surface
KW  - RIXS
Y1  - 2022
U6  - https://doi.org/10.1073/pnas.2118101119
SN  - 1091-6490
VL  - 119
IS  - 28
PB  - National Acad. of Sciences
CY  - Washington, DC
ER  -