Core-hole-induced dynamical effects in the x-ray emission spectrum of liquid methanol

TL;DR

This study models the x-ray emission spectrum of liquid methanol, incorporating dynamical effects from core-hole creation, achieving close agreement with experimental data and revealing the influence of hydrogen-bonding structure.

Contribution

It introduces a semiclassical method to include dynamical effects in XES calculations, accurately capturing experimental spectra and structural influences.

Findings

Excellent match with experimental spectrum including isotope effects

Dynamical effects depend on hydrogen-bonding structure

Spectrum reflects initial molecular structure through dynamical effects

Abstract

We compute the x-ray emission spectrum (XES) of liquid methanol, with the dynamical effects that result from the creation of the core hole included in a semiclassical way. Our method closely reproduces a fully quantum mechanical description of the dynamical effects for relevant one-dimensional models of the hydrogen-bonded methanol molecules. For the liquid we find excellent agreement with the experimental spectrum, including the large isotope effect in the first split peak. The dynamical effects depend sensitively on the initial structure in terms of the local hydrogen-bonding (H-bonding) character; non-donor molecules contribute mainly to the high-energy peak while molecules with a strong donated H-bond contribute to the peak at lower energy. The spectrum thus reflects the initial structure mediated by the dynamical effects that are, however, seen to be crucial in order to reproduce the intensity distribution of the recently measured spectrum.