[symmetry]

The [symmetry] section controls point-group metadata, the guarded abelian integral reduction, and optional experimental symmetry tiers. Labeling can be useful even when reductions are disabled.

Keywords

enabled

Field	Value
Type	string
Default	true
Values	false, true, auto
Used by	symmetry detection

Controls symmetry detection. Set this to false to disable detection and all symmetry-dependent behavior.

point_group

Field	Value
Type	string
Default	auto
Used by	requested point group

Requested point group, or auto for automatic detection.

subgroup

Field	Value
Type	string
Default	auto
Used by	Abelian subgroup selection

Requested Abelian subgroup, or auto for automatic choice.

label_mo

Field	Value
Type	boolean
Default	True
Used by	MO labeling

Labels molecular orbitals by symmetry where possible.

label_states

Field	Value
Type	boolean
Default	True
Used by	response-state labeling

Labels excited states by symmetry where possible.

label_modes

Field	Value
Type	boolean
Default	True
Used by	vibrational-mode labeling

Labels vibrational modes by symmetry where possible.

use_integral_symmetry

Field	Value
Type	string/boolean-like
Default	True
Used by	integral symmetry reduction

Enables the guarded abelian petite-list/skeleton-Fock reduction for supported energy and grad calculations. The default route verifies the AO operator against the overlap matrix, verifies density invariance before each reduced build, and falls back to the complete integral path when a safety condition is not met. ROHF calculations using pFON also stay on the complete C1 integral path because fractional-occupation convergence can be sensitive to the changed summation order. Set this to False to disable integral reduction. The value full requests the experimental non-abelian tier and should be validated against a C1 reference run.

move_to_standard_frame

Field	Value
Type	boolean
Default	False
Used by	integral symmetry reduction

Controls whether a calculation with use_integral_symmetry=true is rotated and translated to a standard symmetry frame before the integral reduction is staged. The default False keeps the molecule in its input frame; OpenQP then uses the corresponding input-frame symmetry operators for the integral and gradient reductions. The no-move route is available for energy and grad calculations and uses the abelian integral-symmetry tier. The non-abelian use_integral_symmetry=full tier requires move_to_standard_frame=true; OpenQP rejects full together with move_to_standard_frame=false instead of silently using a smaller group. As with every integral-symmetry calculation, validate new systems against a run with use_integral_symmetry=false.

[symmetry]
enabled=true
use_integral_symmetry=true
move_to_standard_frame=false

use_response_symmetry

Field	Value
Type	boolean
Default	False
Used by	response solver symmetry reduction

Enables irrep-blocked response updates. The checker marks this as experimental and recommends validating excitation energies against an unblocked run.

tolerance

Field	Value
Type	float
Default	1.0e-5
Used by	symmetry detection

Geometry tolerance for symmetry detection. Must be positive.

strict

Field	Value
Type	boolean
Default	False
Used by	requested/detected group matching

Requires stricter agreement between requested and detected symmetry labels.