This option uses Psi4 to minimize or evaluate the energies of conformers stored in either a chemical table containing 3D structures or a molecular object with an embedded conformational stack.
To run the calculation:
- Prepare a table of 3D conformers, for example using _confGen, or a molecular object with an embedded conformational stack.
- For table input, ensure that hydrogen atoms are present. If using _confGen, disable the option to keep onlyheavy atoms.
- Check that the atomic formal charges are correct.
- Select MolMechanics/Quantum Mechanics/Minimize Evaluate Conformers from table and specify the input table or object (see different tabs at the top of the GUI dialog).
- Choose whether to minimize the conformers or evaluate their energies only.
Each conformer is processed independently:
- Minimization optimizes the geometry of each conformer.
- Energy evaluation calculates the energy of each conformer without changing its geometry.
For a conformational stack, the results are stored back in the stack. For table input, energies are stored in the psi4_ey column.
Energies are expressed in kcal/mol, relative to the lowest-energy conformer within the stack or each group of table entries sharing the same unique SMILES.
Command-line references: minimize quantum and show energy quantum.