vibeqc.SelectedCIOptions¶

class vibeqc.SelectedCIOptions(target_size=100, conv_tol_energy=1e-06, max_iter=50, verbose=0, random_seed=42, pt2_threshold=1e-06, selection_growth_factor=2.0, max_det_per_iter=5000, do_pt2_correction=True, spin_restricted=True, use_davidson=True, davidson_threshold=50, davidson_max_iter=100, davidson_conv_tol=1e-08)[source]¶

Bases: SolverOptions

Options for the Selected-CI solver.

Parameters:

target_size (int)
conv_tol_energy (float)
max_iter (int)
verbose (int)
random_seed (int)
pt2_threshold (float)
selection_growth_factor (float)
max_det_per_iter (int)
do_pt2_correction (bool)
spin_restricted (bool)
use_davidson (bool)
davidson_threshold (int)
davidson_max_iter (int)
davidson_conv_tol (float)

target_size¶

Maximum number of determinants in the variational space.

Type:: int

max_iter¶

Maximum selection + diagonalization cycles.

Type:: int

conv_tol_energy¶

Convergence threshold on total energy change (Hartree).

Type:: float

pt2_threshold¶

Perturbative threshold for selecting new determinants. Lower = more determinants selected per iteration.

Type:: float

selection_growth_factor¶

Max ratio by which the determinant space can grow each iteration.

Type:: float

max_det_per_iter¶

Hard cap on new determinants per iteration.

Type:: int

do_pt2_correction¶

Compute final PT2 energy correction after convergence.

Type:: bool

spin_restricted¶

Use spin-restricted (closed-shell) determinant basis. When True, each Det represents a doubly-occupied spatial-orbital configuration (spin-summed, S_z = 0). When False, uses SpinDet = (alpha_occ, beta_occ) pairs — required for open-shell or broken-spin-symmetry systems (multiplicity > 1).

Type:: bool

use_davidson¶

Use Davidson iterative diagonalization for ndet > davidson_threshold.

Type:: bool

davidson_threshold¶

Switch to Davidson when ndet exceeds this count.

Type:: int

davidson_max_iter¶

Maximum Davidson iterations.

Type:: int

davidson_conv_tol¶

Davidson residual convergence tolerance.

Type:: float

__init__(target_size=100, conv_tol_energy=1e-06, max_iter=50, verbose=0, random_seed=42, pt2_threshold=1e-06, selection_growth_factor=2.0, max_det_per_iter=5000, do_pt2_correction=True, spin_restricted=True, use_davidson=True, davidson_threshold=50, davidson_max_iter=100, davidson_conv_tol=1e-08)¶

Parameters:

target_size (int)
conv_tol_energy (float)
max_iter (int)
verbose (int)
random_seed (int)
pt2_threshold (float)
selection_growth_factor (float)
max_det_per_iter (int)
do_pt2_correction (bool)
spin_restricted (bool)
use_davidson (bool)
davidson_threshold (int)
davidson_max_iter (int)
davidson_conv_tol (float)

Return type:

None

Methods

__init__([target_size, conv_tol_energy, ...])

Attributes

`conv_tol_energy`	Energy convergence threshold (Hartree).
`davidson_conv_tol`
`davidson_max_iter`
`davidson_threshold`
`do_pt2_correction`
`max_det_per_iter`
`max_iter`	Maximum number of macro-iterations.
`pt2_threshold`
`random_seed`	Random seed for reproducibility.
`selection_growth_factor`
`spin_restricted`
`target_size`	Target number of determinants / bond-dimension / constraint set size.
`use_davidson`
`verbose`	0 = silent, 1 = per-iteration, 2 = debug.

pt2_threshold: float = 1e-06¶

selection_growth_factor: float = 2.0¶

max_det_per_iter: int = 5000¶

do_pt2_correction: bool = True¶

spin_restricted: bool = True¶

use_davidson: bool = True¶

davidson_threshold: int = 50¶

davidson_max_iter: int = 100¶

davidson_conv_tol: float = 1e-08¶