TorsiFlex

TorsiFlex generates and analyzes torsional conformers of flexible acyclic molecules to map their conformational space and provide accurate conformer ensembles for molecular modeling.

Key Features:

• Combined LL/HL methodology: Implements a combined low-level/high-level (LL/HL) strategy to balance computational efficiency and accuracy.
• Systematic and stochastic sampling: Performs preconditioned systematic searches and stochastic sampling to comprehensively explore torsional potential energy surfaces.
• Preconditioned search strategy: Leverages chemical knowledge to guide systematic exploration of conformational space.
• Validation and caching: Applies validation tests and stores optimized structures from previous iterations to avoid revisiting explored torsional regions.
• Dual-level optimization: Conducts initial searches at an inexpensive electronic structure level of theory and reoptimizes identified conformers at a higher level of theory.
• Conformational enantiomerism: Considers conformational enantiomers when applicable for chiral molecules.

Scientific Applications:

• Conformational ensemble generation: Produces detailed conformer ensembles for flexible acyclic molecules to support molecular modeling and structure-based studies.
• Chirality and stereoisomer analysis: Characterizes conformational enantiomerism and potential stereoisomers in chiral molecules.
• Amino acid conformational mapping: Applied to the twenty proteinogenic amino acids in their neutral canonical forms, identifying approximately twice as many conformers as previous studies.

Methodology:

Performs a preconditioned systematic search guided by chemical knowledge combined with stochastic sampling, applies validation tests and caching of optimized structures to prevent revisits, and uses a dual-level workflow with initial inexpensive electronic structure searches followed by reoptimization at a higher level of theory while accounting for conformational enantiomerism.