scf_xtpl_helgaker_2¶
- qcdb.scf_xtpl_helgaker_2(mtdname, zLO, valueLO, zHI, valueHI, alpha=1.63, verbose=1)[source]¶
Extrapolation scheme for reference energies with two adjacent zeta-level bases. Used by
qcdb.cbs(). Halkier, Helgaker, Jorgensen, Klopper, & Olsen, Chem. Phys. Lett. 302 (1999) 437-446\[E_{\textrm{total}}^X = E_{\textrm{total}}^{\infty} + \beta e^{-\alpha X}, \alpha = 1.63\]- Parameters:
mtdname (
str) – Method name (e.g., ‘HF’) used in summary printing.zLO (
int) – Zeta number of the smaller basis set in 2-point extrapolation.valueLO (
Union[float,ndarray]) – Energy, gradient, or Hessian value at the smaller basis set in 2-point extrapolation.zHI (
int) – Zeta number of the larger basis set in 2-point extrapolation. Must be zLO + 1.valueHI (
Union[float,ndarray]) – Energy, gradient, or Hessian value at the larger basis set in 2-point extrapolation.verbose (
int) – Controls volume of printing.alpha (
float) – Fitted 2-point parameter.
- Returns:
Eponymous function applied to input zetas and values; type from valueLO.
- Return type:
Examples
>>> # [1] Hartree-Fock extrapolation >>> qcdb.energy(qcdb.cbs, scf_wfn='hf', scf_basis='cc-pV[DT]Z', scf_scheme=qcdb.scf_xtpl_helgaker_2)
