SULISO

SULISO computes vibrational frequencies and isotope effects to analyze molecular vibrations and isotopic fractionation across chemistry, biology, and earth sciences.

Key Features:

• Modular suite: Comprises four programs—CAMVIB, LIPFR, UJISO, and CUTOFF—that address different aspects of vibrational spectroscopy and isotopic studies.
• Vibrational frequency and isotope-effect calculations: Performs calculation and analysis of vibrational frequencies and isotope effects.
• CAMVIB: Analyzes calculated harmonic frequencies and normal modes and interprets them in terms of internal coordinates.
• LIPFR: Calculates isotopic partition function ratios for pairs of isotopically substituted whole molecules using conventional methodologies.
• UJISO: Calculates isotopic partition function ratios for specified subsets of atoms within very large systems.
• CUTOFF: Truncates large force-constant matrices to produce smaller matrices corresponding to specified subsets of atoms.

Scientific Applications:

• Probing reaction mechanisms: Uses isotope effects as probes into chemical reaction mechanisms.
• Environmental interpretation: Supports inference of environmental conditions from isotopic signatures.
• Molecular dynamics: Provides insights into molecular vibrations and dynamics through harmonic frequency and normal mode analysis.
• Biochemical pathway analysis: Applies isotopic partition function calculations to studies of biochemical pathways.
• Geological processes: Enables isotopic analysis relevant to geological and earth science investigations.

Methodology:

Calculation and analysis of vibrational frequencies and isotope effects; analysis of calculated harmonic frequencies and normal modes in internal coordinates; computation of isotopic partition function ratios for whole molecules and for atom subsets; truncation of force-constant matrices to subsets of atoms.