CCM.three_body_utils

Provides functions for all of the 3 body interactions

Functions

get_3NF(part, hole, my3body)

This routine takes the relatively small number of three-body matrix elements in mycontact and sorts them into the four-indexed interaction tensors.

get_3NF_Eref(w_hhh_hhh)

returns normal-ordering contributions to the reference energy

get_3NF_fock(hnum, pnum, w_phh_phh, ...)

gets the normal-ordering contributions of the three-body potential to the Fock matrix

get_3NF_tbme(w_pph_pph, w_pph_phh, ...[, ...])

Finds the normal-ordering contributions of the three-body potential to the two-body matrix elements

order_state(ket, lookup_p, lookup_h, i1, i2, i3)

orders tuple into right order, i.e. "p" before "h" this function is used by the function get_3NF.
CCM.three_body_utils.get_3NF(part, hole, my3body)

This routine takes the relatively small number of three-body matrix elements in mycontact and sorts them into the four-indexed interaction tensors. It also anti-symmetrizes the latter whenin and out indices run over the same set of particle/hole indices. The whole thing is a bit tedious but much faster than the function load2bme

Parameters:

  • part (list[int]) – list of particle-space indices

  • hole (list[int]) – list of hole-space indices

  • my3body (list[(int, int, int, int, int, int, float)]) – list of three-body matrix elements

Returns:

w_ppp_pph, w_ppp_phh, w_pph_pph, w_ppp_hhh, w_pph_phh, w_pph_hhh, w_phh_phh, w_phh_hhh, w_hhh_hhh as lists of nonzeros

Return type:

9 list[(int, int, int, int, int, int, float)]

CCM.three_body_utils.order_state(ket, lookup_p, lookup_h, i1, i2, i3)

orders tuple into right order, i.e. “p” before “h” this function is used by the function get_3NF

Parameters:

  • ket ((str, str, str)) – ket to be used in finding the right particle hole index

  • lookup_p (dict(int, int)) – dictionary to lookup the index of particles

  • lookup_h (dict(int, int)) – dictionary to lookup the index of holes

  • i1 (int) – index of first particle/hole

  • i2 (int) – index of second particle/hole

  • i3 (int) – index of third particle/hole

Returns:

the correctly ordered result looking like ket, the sign of the permutation that achieved this, and the list of three single-particle indices

Return type:

tuple(str, str, str), float, list[(int, int, int)]

CCM.three_body_utils.get_3NF_Eref(w_hhh_hhh)

returns normal-ordering contributions to the reference energy

Parameters:

w_hhh_hhh (list[(int, int, int, int, int, int, float)]) – nonzero elements of the three body interaction W^{ijk}_{lmn}

Returns:

contribution to the reference energy from the normal ordered three nucleon force

Return type:

float

CCM.three_body_utils.get_3NF_fock(hnum, pnum, w_phh_phh, w_phh_hhh, w_hhh_hhh)

gets the normal-ordering contributions of the three-body potential to the Fock matrix

Parameters:

  • hnum (int) – number of hole states

  • pnum (int) – number of particle states

  • w_phh_phh (list[(int, int, int, int, int, int, float)]) – nonzero elements of the three body interaction matrix W^{aij}_{bkl}

  • w_phh_hhh (list[(int, int, int, int, int, int, float)]) – nonzero elements of the three body interaction matrix W^{aij}_{klm}

  • w_hhh_hhh (list[(int, int, int, int, int, int, float)]) – nonzero elements of the three body interaction matrix W^{ijk}_{lmn}

Returns:

contributions to the normal ordered one body matrices

Return type:

numpy array, numpy array, numpy array

CCM.three_body_utils.get_3NF_tbme(w_pph_pph, w_pph_phh, w_pph_hhh, w_phh_phh, w_phh_hhh, w_hhh_hhh, pnum, hnum, sparse_pppp=True, sparse_ppph=True)

Finds the normal-ordering contributions of the three-body potential to the two-body matrix elements

Parameters:

  • w_pph_pph (list[(int, int, int, int, int, int, float)]) – nonzero elements of the three body interaction matrix W^{abi}_{cdj}

  • w_pph_phh (list[(int, int, int, int, int, int, float)]) – nonzero elements of the three body interaction matrix W^{acj}_{bkl}

  • w_phh_phh (list[(int, int, int, int, int, int, float)]) – nonzero elements of the three body interaction matrix W^{aij}_{bkl}

  • w_phh_hhh (list[(int, int, int, int, int, int, float)]) – nonzero elements of the three body interaction matrix W^{aij}_{klm}

  • w_hhh_hhh (list[(int, int, int, int, int, int, float)]) – nonzero elements of the three body interaction matrix W^{ijk}_{lmn}

  • hnum (int) – number of hole states

  • pnum (int) – number of particle states

  • sparse_pppp (bool) – Optional; whether or not v_pppp should be stored as sparse or not

  • sparse_ppph (bool) – Optional; whether or not v_ppph should be stored as sparse or not

Returns:

contributions to the normal ordered two body matrices

Return type:

numpy array, numpy array, numpy array, numpy array, numpy array, numpy array