Capturing Fingerprints of Conical Intersection: Complementary Information of Non-Adiabatic Dynamics from Linear X-ray Probes

TL;DR

This paper proposes a method using combined X-ray pump-probe techniques to directly observe conical intersections in non-adiabatic molecular dynamics, overcoming previous bandwidth limitations.

Contribution

It introduces a theoretical approach combining multiple X-ray spectroscopies to identify conical intersections in molecules.

Findings

Demonstrates the potential of combined X-ray techniques to detect conical intersections.

Provides theoretical evidence for conical intersection in pyrrole.

Suggests new experimental strategies for observing non-adiabatic dynamics.

Abstract

Many recent experimental ultrafast spectroscopy studies have hinted at non-adiabatic dynamics indicating the existence of conical intersections, but their direct observation remains a challenge. The rapid change of the energy gap between the electronic states complicated their observation by requiring bandwidths of several electron volts. In this manuscript, we propose to use the combined information of different X-ray pump-probe techniques to identify the conical intersection. We theoretically study the conical intersection in pyrrole using transient X-ray absorption, time-resolved X-ray spontaneous emission, and linear off-resonant Raman spectroscopy to gather evidence of the curve crossing.