Psi4 QM Conformer Ensemble

Generate all low-energy conformers of the input molecule. A large ensemble of potential conformations are generated using OpenEye toolkits, through exhaustive sampling of ring conformations, torsions, and hydrogens. To customize torsions rules used for this conformer generation, use output from the Psi4 QM Fragmentation and Torsion Scanning Floe.

Next, the generated conformers are optimized using Psi4 at a low level of QM theory with all torsions constrained. The conformers are filtered to remove exact duplicates. Next, the energies are corrected to a higher level of QM theory through a single-point energy calculation. Last, high-strain conformations are removed at the specified energy cutoff.

Conformers are generated for the input molecule, thus, if the primary molecule has multiple conformers they are ignored.

This Floe assumes that all input molecules are a part of the same ensemble. Since conformers are generated at the beginning, there is no reason to provide more than one input molecule. However, this Floe will also work with multiple tautomers of the same molecule, if they are provided as input. The energy window is applied across all tautomers.

Extra Required Parameters

• Psi4 Conformer Ensemble Output (dataset_out) : Dataset to store optimized conformers in the specified energy window, each record has a single conformer.

  Default: confs_psi4_gopt_spe
• Intermediate Optimization Output (dataset_out) : Dataset to store QM optimized conformers before deduplication. If a job is cancelled early (either by the user or hitting a cost threshold is reached), these intermediate optimized conformers, will still be saved.

  Default: all_conf_gopt
• Input Dataset (data_source) : The dataset(s) to read records from
• Failure Output (dataset_out) : Dataset to store records which fail during this floe.

  Default: psi4_conf_ens_failures