Molecular structure retrieval directly from laboratory-frame photoelectron spectra in laser-induced electron...

Area of Science:

• Molecular Physics
• Quantum Chemistry
• Spectroscopy

Background:

• Retrieving molecular geometry (bond distances, angles) from scattering data is challenging for conventional methods, especially for large or dynamic systems.
• Existing pattern matching and fitting algorithms often require significant computational resources and a priori knowledge.
• Accurate molecular structure determination is crucial for understanding chemical reactions and molecular properties.

Purpose of the Study:

• To introduce a novel, simplified method for retrieving molecular structure from laser-induced electron diffraction (LIED) data.
• To demonstrate the effectiveness of this new method by comparing it with established Fourier-based techniques.
• To validate the retrieval of a specific molecular configuration using quantum-classical calculations.

Main Methods:

• Utilized laser-induced electron diffraction (LIED) to probe isolated gas-phase molecules.
• Developed a retrieval method based on identifying critical points in the oscillating molecular interference scattering signal.
• Extracted the scattering signal directly from the laboratory-frame photoelectron spectrum.
• Performed quantum-classical calculations to confirm the retrieved molecular structure.

Main Results:

• The novel critical point identification method successfully retrieved the molecular structure.
• The method demonstrated comparable accuracy to traditional Fourier-based retrieval techniques.
• The asymmetrically stretched and bent field-dressed configuration of carbonyl sulfide (OCS) was accurately determined.
• Quantum-classical calculations validated the experimental findings.

Conclusions:

• The proposed simple retrieval method offers a powerful and efficient approach for determining precise molecular configurations from LIED data.
• This technique overcomes limitations of traditional methods, particularly for systems with limited prior information.
• LIED, combined with this new retrieval strategy, provides attosecond temporal and picometre spatial resolution for molecular structure analysis.