UCCSD.compute_excitation_lists

static UCCSD.compute_excitation_lists(num_particles, num_orbitals, active_occ_list=None, active_unocc_list=None, same_spin_doubles=True, method_singles='both', method_doubles='ucc', excitation_type='sd')[source]

Computes single and double excitation lists.

Parameters

  • num_particles (Union(list, int)) – number of particles, if it is a tuple, the first number is alpha and the second number if beta.

  • num_orbitals (int) – Total number of spin orbitals

  • active_occ_list (list) – List of occupied orbitals to include, indices are 0 to n where n is max(num_alpha, num_beta)

  • active_unocc_list (list) – List of unoccupied orbitals to include, indices are 0 to m where m is num_orbitals // 2 - min(num_alpha, num_beta)

  • same_spin_doubles (bool) – True to include alpha,alpha and beta,beta double excitations as well as alpha,beta pairings. False includes only alpha,beta

  • excitation_type (str) – choose ‘sd’, ‘s’, ‘d’ to compute q-UCCSD, q-UCCS, q-UCCD excitation lists

  • method_singles (str) – specify type of single excitations, ‘alpha’, ‘beta’, ‘both’ only alpha or beta spin-orbital single excitations or both (all single excitations)

  • method_doubles (str) – choose method for double excitations ‘ucc’ (conventional ucc), ‘succ’ (singlet ucc), ‘succ_full’ (singlet ucc full), ‘pucc’ (pair ucc)

Returns

Single excitation list list: Double excitation list

Return type

list

Raises

  • ValueError – invalid setting of number of particles

  • ValueError – invalid setting of number of orbitals