Singular value decomposition analysis of the electron density changes occurring upon electrostatic polarization of water

In-depth elucidation of how molecules are electrically polarized would be one key factor for understanding the properties of those molecules under various thermodynamic and/or spatial conditions. Here this problem is tackled for the case of hydrogen-bonded water by conducting singular value decomposition of the electron density changes that occur upon electrostatic polarization. It is shown that all those electron density changes are approximately described as linear combinations of ten orthonormal basis vectors. One main component is the interatomic charge transfer through each OH bond, while some others are characterized as the atomic dipolar polarizations, meaning that both of these components are important for the electrostatic polarization of water. The interaction parameters that reasonably well reproduce the induced dipole moments are derived, which indicate the extent of mixing of the two components in electrostatic polarization.

Automated summary

This study investigates the problem of electrical polarization of hydrogen-bonded water through singular value decomposition. It shows that all electron density changes can be approximately described as linear combinations of ten orthonormal basis vectors. One main component is the interatomic charge transfer through each OH bond, while some others are characterized as atomic dipolar polarizations. The results of this study are important for understanding the process of electrostatic polarization of water.