Ground state calculations

This library provides three Hartree-Fock solvers, they are:

  • Hartree-Fock solver with general spin-orbitals, HartreeFock.

  • The restricted Hartree-Fock method, RHF.

  • The unrestricted Hartree-Fock method, UHF.

All classes re-use the self-consistent field procedure defined in the HartreeFock-class, but implement their own methods where needed, e.g., the construction of the Fock matrix.

class hartree_fock.hf.HartreeFock(system, mixer=<class 'hartree_fock.mix.DIIS'>, verbose=False)

Hartree Fock Abstract class

Abstract base class defining the skeleton of a Hartree Fock ground state solver class.

Parameters

  • system (QuantumSystems) – Quantum systems class instance

  • mixer (AlphaMixer) – AlpaMixer object

  • verbose (bool) – Prints iterations for ground state computation if True

change_basis()

Function changing the system basis to the Hartree-Fock basis.

compute_particle_density()

Computes one-particle density :returns: Particle density :rtype: np.array

static diagonalize(A, S)

Solve the generalized eigenvalue problem AC = SCE, where E = diag(e1,…,eL)

initial_guess(key)

Various initial guesses are used in the litterature.

class hartree_fock.rhf.RHF(system, mixer=<class 'hartree_fock.mix.DIIS'>, verbose=False)
class hartree_fock.uhf.UHF(system, **kwargs)