# Copyright (c) 2015-2018 Commissariat à l'énergie atomique et aux énergies alternatives (CEA)
# Copyright (c) 2015-2018 Centre national de la recherche scientifique (CNRS)
# Copyright (c) 2018-2021 Simons Foundation
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You may obtain a copy of the License at
# https:#www.gnu.org/licenses/gpl-3.0.txt
#
# Authors: Michel Ferrero, Priyanka Seth, Nils Wentzell
from itertools import product
# Set function to make index for GF blocks given spin sn and orbital name on
[docs]
def get_mkind(off_diag,map_operator_structure):
r"""
Set function that makes the index for operators and GF blocks for a given
spin and orbital name.
Parameters
----------
off_diag : boolean
Do we have (orbital) off-diagonal elements?
If yes, the operators and blocks are denoted by ('spin', 'orbital'), otherwise by ('spin_orbital',0).
map_operator_structure : dict
Mapping of names of GF blocks names from one convention to another,
e.g. {('up', 0): ('up_0', 0), ('down', 0): ('down_0',0)}.
If provided, the operators and blocks are denoted by the mapping of ``('spin', 'orbital')``.
Returns
-------
mkind : lambda
The function mapping spin and orbital names to a tuple.
"""
if (off_diag is None) and (map_operator_structure is None):
raise ValueError("hamiltonians: provide either off_diag or map_operator_structure.")
if map_operator_structure is None:
if off_diag:
mkind = lambda sn, on: (sn, on)
else:
mkind = lambda sn, on: (sn+'_%s'%on, 0)
else:
mkind = lambda sn, on: map_operator_structure[(sn,on)]
return mkind
# Set block structure of GF
[docs]
def set_operator_structure(spin_names,n_orb,off_diag):
r"""
Set the operator_structure for given spin and orbital names, according to
whether or not the Green's functions contain off-diagonal blocks.
Parameters
----------
spin_names : list of strings
Names of the spins, e.g. ['up','down'].
n_orb : int
Number of orbitals.
off_diag : boolean
Do we have (orbital) off-diagonal elements?
If yes, the operators and blocks are denoted by ('spin', 'orbital'),
otherwise by ('spin_orbital',0).
Returns
-------
op_struct : list
The structure of the operators [block:[inner], ... ].
"""
if isinstance(n_orb, list):
import warnings
warnings.warn("set_operator_structure takes as a second argument the number of orbitals, not a list of orbital names")
n_orb = len(n_orb)
op_struct = []
if off_diag: # outer blocks are spin blocks
for sn in spin_names:
op_struct.append([sn, n_orb])
else: # outer blocks are spin-orbital blocks
for sn, on in product(spin_names,range(n_orb)):
op_struct.append([sn+'_%s'%on, 1])
return op_struct