The Fock space method of vibrational analysis.

Area of Science:

• Quantum mechanics
• Spectroscopy
• Chemical physics

Background:

• Semiclassical theory is essential for interpreting complex vibrational spectra.
• Existing methods face challenges in providing detailed dynamical assignments.

Purpose of the Study:

• To present a reformulated semiclassical theory for interpreting complex multiresonant vibrational spectra.
• To introduce novel wave function representations for enhanced spectral analysis.

Main Methods:

• The study utilizes a reformulated semiclassical theory based on the spectroscopic Hamiltonian.
• It involves computing phase space trajectories to understand quantized motions.
• New projected representations in action and angle spaces are introduced.

Main Results:

• The new formulation provides level-by-level dynamical assignments without further computation.
• Projected representations reduce the dimensionality of angle and action spaces.
• A more complete assignment of the thiophosgene spectrum was achieved using the lattice representation.

Conclusions:

• The reformulated semiclassical theory offers a powerful tool for interpreting complex vibrational spectra.
• The novel representations facilitate more detailed and efficient spectral assignments.
• This approach advances the understanding of molecular dynamics through spectral analysis.