Spin State Prediction

Molecules can exist in a variety of different spin states, where not all of the electrons are paired up. It is critical that all calculations are being performed on the correct spin state, as the properties of a molecule can vary significantly depending on the spin state.

How It Works

Rowan's spin state prediction workflow determines the energies of the possible spin states of a molecule. It optimizes the molecule for all spin states, and then computes the energy with a more accurate method. The calculations can be done in solvent, and frequencies can be calculated as well.

The levels of theory used for optimization and single-point-energy calculation depend on the mode selected by the user.

Modes

Rowan's spin state prediction workflow can be run in one of four modes: "Reckless," "Rapid," "Careful," and "Meticulous." Each mode uses a different combination of optimization and single-point methods to balance speed and accuracy. Reckless is incredibly fast, and useful for initial exploration. Rapid is recommended for most routine work, and runs very quickly. Careful produces publication quality results, but is significantly slower than Rapid. Meticulous produces the most accurate results, but is typically only needed for the most demanding of systems, as it can be incredibly expensive.

"Rapid" is recommended for most work, while "Careful" is recommended for publication quality results.