vibeqc.compute_gcp¶

vibeqc.compute_gcp(mol, basis_name=None, *, params=None, with_gradient=False, damping=None)[source]¶

Geometric counterpoise correction (Kruse & Grimme 2012).

Parameters:

mol (vibeqc._vibeqc_core.Molecule) – vibeqc.Molecule (atomic positions in bohr; the gCP evaluator works in bohr natively).
basis_name (str | None) – Lowercase canonical name of the target basis set (e.g. "def2-svp", "minis", "def2-mtzvpp"). Looked up in the bundled parameter registry. Mutually exclusive with params.
params (GCPParams | None) – Explicit GCPParams instance — bypasses the registry lookup. Use this to plug in published per-element data for a basis that’s not yet bundled, or to evaluate gCP with a custom parameter set.
with_gradient (bool) – If True, the returned GCPResult carries an (n_atoms, 3) array of ∂E_gCP/∂R_A in Hartree/bohr. The gCP energy is a closed-form sum over atom pairs; the gradient is the analytic derivative of the same expression with respect to nuclear positions. Not yet available together with damping (raises NotImplementedError).
damping (tuple | None) – Optional (dmp_scal, dmp_exp) tuple enabling the short-range “damped gCP” used by the pbeh-3c / hse-3c / r2scan-3c composites (gcp.f90 damp=.true. path; Grimme group default (4.0, 6.0)). Each pair contribution is scaled by 1 - 1/(1 + dmp_scal·(R/r0ab)^dmp_exp), which suppresses the bonded-pair gCP so only genuine long-range (intermolecular) BSSE survives. None (default) reproduces the plain Kruse-Grimme gCP — unchanged for every non-damped caller (def2-svp, minix, b3lyp-3c, standalone use). Without damping an isolated molecule’s gCP is grossly over-counted (audit F1.5: r2scan-3c/H2O gives +28.8 undamped vs the correct +1.12 kcal/mol damped).

Return type:

GCPResult

Raises:

ValueError – If neither basis_name nor params is given, or if both are.
GCPDataMissing – If the basis-set / element combination falls outside the bundled parameter coverage. The message lists the missing elements and points at the contribute-via-PR pathway.