#### Single Point Energy

GPU-accelerated density functional theory methods using Gaussian orbital basis sets.

Features:

- Density functional approximations including LDA, GGA, Meta-GGA, hybrid (full exchange and range-separated exchange).
- Empirical and non-local dispersion corrections available.
- Support for basis sets with arbitrary angular momentum.
- Support for effective core potentials.
- Continuum solvent available via PCM.
- Excited state calculations possible with time-dependent density functional theory.

#### Geometry Optimization

Locate equilibrium geometries of molecules in their ground or excited states.

Did you know?

- Analytic gradients are available for all methods.
- Many types of constraints are supported.
- Input structure doesn't need to satisfy constraints.

Method:

Locate equilibrium geometries of molecules in their ground or excited states.

Outputs:

- Equilibrium structure subject to any specified constraints.

Types of questions you can answer:

- What shape is the molecule?

#### Conformer Search

Find the energies of all low-lying equilibrium structures.

Did you know?

- Multiple input formats supported including SMILES strings.
- Highly customizable range of filters including density functionals, molecular mechanics, and machine learned force fields.

Method:

Molecular mechanics and neural network potentials for initial screening of conformers. DFT optimization and single points for accurate final energies and structures.

Outputs:

- Equilibrium structures for each conformer.
- Relative energies and Boltzmann populations.

Types of questions you can answer:

- Find distribution of effective molecule shapes and corresponding energies.

#### Torsion scan

Compute the potential energy of rotations about bonds in molecules.

Did you know?

- Bond selection is available through our GUI.
- Calculation of the torsional potential is automatically parallelized over many GPUs.

Method:

A series of constrained optimizations is performed using DFT to obtain the torsional potential.

Outputs:

- Potential energy curve along the torsion.
- Optimized geometries at each value of the torsion.

Types of questions you can answer:

- Find active conformation of molecules.
- Quantify rates of interconversion between conformers.

#### F-SAPT

Computes the interaction energy between noncovalently bonded molecules, provides a decomposition of that interaction into physically meaningful components (i.e. electrostatics, dispersion, etc.) and allows the interaction to be partitioned into fragment-pair contributions.

Did you know?

- The setup of F-SAPT calculations of protein-ligand complexes has been automated.
- You can compare two F-SAPT results on similar complexes. E.g. Two similar ligands interacting with the same target.

Method:

The interaction energy is computed using symmetry-adapted perturbation theory (SAPT) and allows the functional group SAPT (F-SAPT) partitioning to be applied.

Outputs:

- Interaction energy of a nonbonded complex.
- Physical contributions to the interaction energy: electrostatics, exchange (steric repulsion), induction (polarization) and dispersion components.
- A partition of the interaction components into user defined fragment pairwise contributions.

Types of questions you can answer:

- Why is a particular interaction favorable or unfavorable? What is the physical origin of that interaction?
- What pairwise interactions are favorable and unfavorable? Why?
- How do two molecules differ in how they interact with the same target?

#### Interaction energy

Compute the interaction energy between two non-bonded molecules.

Did you know?

- Basis set superposition error is automatically removed.
- Highly accurate results can be obtained with the ωB97M-V functional.

Method:

Interaction energies are computed using the Boys-Bernardi counterpoise correction.

Outputs:

- Interaction energy of a non-covalent dimer.
- Quantification of the basis set superposition error in that interaction energy.

Types of questions you can answer:

- Quantify the strength of interactions within non-bonded complexes.
- Test the effect of chemical substitutions on non-bonded interactions.

#### Transition States

Locate transition state structures.

Transition state optimization is available through the following workflows:

- Transition States: Starts from a user-supplied guess of the transition state geometry.
- Reactant-Product Transition State Optimization: Starts from user-supplied guesses of the reactant and product geometries.

Did you know?

- A secondary lower level of theory can be selected by the user to accelerate the calculation.
- Vibrational frequencies can be calculated at the optimized transition state.
- A transition state optimization can be started from the reactant and product geometries.
- A single structure guess can also be obtained from the reaction path tool.

Method:

Transition state is optimized by partitioned rational function optimization using an exact eigenvector following algorithm.

Outputs:

- Energy and geometry of the transition state.
- (Optionally) Vibrational frequencies at the transition state.

Types of questions you can answer:

- Find energetic barriers to chemical reactions.
- Compute reaction rate constants.
- Identify chemical reaction mechanisms.

#### Reaction Path Optimization

Identify the minimum energy path connecting reactants and products.

Did you know?

- Optimization of the endpoints can be performed as part of this workflow.
- Interpolation of the reaction path is performed automatically.
- The result of a reaction path optimization can be used to initiate a transition state optimization.

Method:

The nudged elastic band (NEB) method is used to define the reaction path. NEB force constants are adjustable to provide increased resolution near the transition state.

Outputs:

- Reaction energy and barriers.
- Approximate transition state geometry.
- Optimized structures along the path.

Types of questions you can answer:

- Find reaction energies and energetic barriers to chemical reactions.
- Compute reaction rate constants.
- Identify chemical reaction mechanisms.