Basic Calculation

Configuration

Use the exported enums instead of raw strings when setting the method and engine:

import rowan

molecule = rowan.Molecule.from_smiles("CCO")
workflow = rowan.submit_basic_calculation_workflow(
    initial_molecule=molecule,
    tasks=["optimize"],
    method=rowan.Method.GFN2_XTB,
    engine=rowan.Engine.XTB,
)

Pass an OptimizationSettings object or an equivalent dictionary to opt_settings. optimize_cell defaults to False; set it to True only when optimizing a periodic cell.

opt_settings = rowan.OptimizationSettings(max_steps=200, optimize_cell=False)

Basic calculation workflow - perform quantum chemical calculations.

BasicCalculationResult dataclass

BasicCalculationResult(workflow_data: dict[str, Any], workflow_type: str, workflow_uuid: str, complete: bool = True)

Bases: WorkflowResult

Result from a basic-calculation workflow.

calculation_uuid property

calculation_uuid: str | None

The UUID of the calculation.

calculation property

calculation: Calculation | None

Lazily fetched Calculation object with full molecule data.

molecule property

molecule: Molecule | None

The final molecule geometry with all computed properties.

molecules property

molecules: list[Molecule]

All molecules from the calculation (e.g., optimization trajectory).

energy property

energy: float | None

Energy of the final molecule (Hartree).

charges property

charges: list[float] | None

Partial charges on each atom.

spin_densities property

spin_densities: list[float] | None

Spin densities on each atom (for open-shell systems).

dipole property

dipole: tuple[float, float, float] | None

Dipole moment vector (Debye).

frequencies property

frequencies: list[float] | None

Vibrational frequencies in cm^-1 (if frequency calculation was performed).

symmetry property

symmetry: str | int | None

Space group number (1–230) or point group symbol.

xrd_peaks property

xrd_peaks: list[tuple[int, int, int, float]] | None

XRD reflections as (h, k, l, intensity) tuples.

band_structure property

band_structure: BandStructure | None

Electronic band structure and DOS (periodic systems only).

band_gap property

band_gap: float | None

Band gap (Hartree).

density_of_states property

density_of_states: list[tuple[float, float]] | None

Total DOS as (energy in Hartree, k-weighted count) pairs (Fermi level = 0).

elastic_tensor property

elastic_tensor: tuple[tuple[float, float, float, float, float, float], tuple[float, float, float, float, float, float], tuple[float, float, float, float, float, float], tuple[float, float, float, float, float, float], tuple[float, float, float, float, float, float], tuple[float, float, float, float, float, float]] | None

Elastic stiffness matrix in GPa (Voigt order: xx yy zz yz xz xy).

optimization_energies

optimization_energies(relative: bool = False) -> list[float]

Energies for each optimization step.

Parameters:

Name	Type	Description	Default
relative	bool	return relative energies in kcal/mol (relative to the lowest energy step). If False (default), return absolute energies in Hartree	False

Returns:

Type	Description
list[float]	list of energies for each optimization step

settings_from_preset

settings_from_preset(preset: PresetName, **overrides: Any) -> stjames.Settings

Construct a Settings object from a named preset.

Parameters:

Name	Type	Description	Default
preset	PresetName	preset name – see PresetName for options	required
overrides	Any	any Settings fields to override (e.g. tasks, mode, solvent_settings)	{}

Returns:

Type	Description
Settings	validated Settings object

Raises:

Type	Description
ValueError	an unknown preset name is given

submit_basic_calculation_workflow

submit_basic_calculation_workflow(initial_molecule: StructureInput, tasks: list[str], method: Method | str | None = None, basis_set: BasisSet | str | None = None, mode: str = 'auto', engine: Engine | str | None = None, corrections: list[str] | None = None, solvent_settings: SolventSettings | dict[str, Any] | None = None, opt_settings: OptimizationSettings | dict[str, Any] | None = None, pbc_dft_settings: PBCDFTSettings | dict[str, Any] | None = None, excited_state_settings: TDDFTSettings | dict[str, Any] | None = None, preset: PresetName | None = None, name: str = 'Basic Calculation Workflow', folder_uuid: str | None = None, folder: Folder | None = None, max_credits: int | None = None, webhook_url: str | None = None, is_draft: bool = False) -> Workflow[BasicCalculationResult]

Submit a basic-calculation workflow to the API.

Parameters:

Name	Type	Description	Default
initial_molecule	StructureInput	molecule to perform the calculation on	required
tasks	list[str]	tasks to perform, see Task (e.g. optimize, energy, frequencies)	required
method	Method | str | None	computational method, see Method. Default: omol25_conserving_s	None
basis_set	BasisSet | str | None	basis set, see BasisSet	None
mode	str	accuracy mode, see Mode. Default: auto	'auto'
engine	Engine | str | None	compute engine, see Engine. Auto-selected from method if not specified	None
corrections	list[str] | None	dispersion corrections, see Correction	None
solvent_settings	SolventSettings | dict[str, Any] | None	solvent settings as a dict or SolventSettings	None
opt_settings	OptimizationSettings | dict[str, Any] | None	optimization settings as a dict or OptimizationSettings	None
pbc_dft_settings	PBCDFTSettings | dict[str, Any] | None	periodic boundary condition DFT settings as a dict or PBCDFTSettings. Specifies the plane-wave cutoff (Hartree), Monkhorst–Pack k-point grid, and optional smearing. When set, the engine is automatically set to Quantum ESPRESSO unless engine is explicitly provided	None
excited_state_settings	TDDFTSettings | dict[str, Any] | None	excited-state settings for TDDFT calculations	None
preset	PresetName | None	named preset, mutually exclusive with method/engine/basis_set/corrections. - general_nnp – omol25_conserving_s on omol25 - organic_nnp – aimnet2_wb97md3 on aimnet2 - rapid_semiempirical – gfn2_xtb on xtb - routine_dft – r2scan-D4/vDZP on gpu4pyscf - careful_dft – wb97m_d3bj/vDZP on gpu4pyscf	None
name	str	workflow name	'Basic Calculation Workflow'
folder_uuid	str | None	UUID of the folder to place the workflow in	None
folder	Folder | None	folder to place the workflow in	None
max_credits	int | None	maximum credits to use	None
webhook_url	str | None	URL that Rowan will POST to when the workflow completes	None
is_draft	bool	save as a draft without starting execution	False

Returns:

Type	Description
Workflow[BasicCalculationResult]	submitted workflow

Raises:

Type	Description
HTTPStatusError	API request fails
ValueError	preset is combined with method/engine/basis_set/corrections

To resubmit with identical settings insulated from future preset changes, use submit_workflow directly with workflow_data from a previous result.