forte2.scf.ghf

Module Contents

class forte2.scf.ghf.GHF

Bases: forte2.scf.scf_base.SCFBase

Generalized Hartree-Fock (GHF) method. The GHF spinor basis is a direct product of the atomic basis and \(\{|\alpha\rangle, |\beta\rangle\}\):

\[|\psi_i\rangle = \sum_{\mu} \sum_{\sigma\in\{\alpha,\beta\}} c^{\sigma}_{\mu i} |\chi_{\mu}\rangle\otimes|\sigma\rangle\]

The MO coefficients are stored in a square array

\[\begin{split}\mathbf{C} = \begin{bmatrix} \mathbf{c}^{\alpha}_0 & \mathbf{c}^{\alpha}_1 & \dots\\ \mathbf{c}^{\beta}_0 & \mathbf{c}^{\beta}_1 & \dots \end{bmatrix}\end{split}\]

Parameters:

guess_mixbool, optional, default=False

If True, will mix the HOMO and LUMO orbitals to try to break alpha-beta degeneracy if nel is even.

alpha_beta_mixbool, optional, default=False

If True, will mix the highest two spinorbitals to try to seed alpha-beta orbital gradients.

break_complex_symmetrybool, optional, default=False

If True, will add a small complex perturbation to the initial density matrix. This will both break the complex conjugation symmetry and Sz symmetry (allowing alpha-beta density matrix blocks to be nonzero)

j_adapt: bool, optional, default=False

If True, the j-adapted spinor AO basis will be used instead of the spherical AO basis.

ms_guess: float = None

guess_mix: bool = False

alpha_beta_mix: bool = False

break_complex_symmetry: bool = False

j_adapt: bool = False