preparation of Slater determinants and fermionic Gaussian states

.pylintdict

@@ -53,6 +53,7 @@ cargs
 cartesian
 cbit
 ccx
+cdots
 cfg
 chc
 chiral
@@ -109,6 +110,7 @@ dimensionality
 discoverable
 distinguishability
 dll
+docstring
 dof
 doi
 dt
@@ -226,6 +228,7 @@ kwarg
 kwargs
 labelled
 lda
+ldots
 len
 leucine
 levinthal
@@ -240,6 +243,7 @@ ljik
 lk
 logfile
 lookback
+lvert
 lysine
 macos
 majorana
@@ -312,6 +316,7 @@ ortho
 orthonormal
 otimes
 outpath
+overline
 pac
 param
 parameterized
@@ -359,6 +364,7 @@ qubit
 qubits
 qutrit
 radians
+rangle
 rcccx
 rccx
 readme
@@ -401,6 +407,7 @@ setia
 setted
 shende
 sklearn
+slater
 spinop
 springer
 spsa

qiskit_nature/circuit/library/__init__.py

@@ -1,6 +1,6 @@
 # This code is part of Qiskit.
 #
-# (C) Copyright IBM 2020, 2021.
+# (C) Copyright IBM 2020, 2022.
 #
 # This code is licensed under the Apache License, Version 2.0. You may
 # obtain a copy of this license in the LICENSE.txt file in the root directory
@@ -14,7 +14,7 @@
 Circuit Library (:mod:`qiskit_nature.circuit.library`)
 ======================================================
 
-A collection of circuits used as building blocks or inputs for algorithms.
+A collection of gates and circuits used as building blocks or inputs for algorithms.
 
 .. currentmodule:: qiskit_nature.circuit.library
 
@@ -25,7 +25,9 @@
    :toctree: ../stubs/
    :nosignatures:
 
+   FermionicGaussianState
    HartreeFock
+   SlaterDeterminant
    VSCF
 
 Ansatzes
@@ -64,7 +66,7 @@
     UVCCSD,
 )
 
-from .initial_states import HartreeFock, VSCF
+from .initial_states import FermionicGaussianState, HartreeFock, SlaterDeterminant, VSCF
 
 __all__ = [
     "UCC",
@@ -76,4 +78,6 @@
     "UVCC",
     "UVCCSD",
     "VSCF",
+    "FermionicGaussianState",
+    "SlaterDeterminant",
 ]

qiskit_nature/circuit/library/initial_states/__init__.py

@@ -11,7 +11,8 @@
 # that they have been altered from the originals.
 """Qiskit Nature Circuit Library Initial States."""
 
+from .fermionic_gaussian_states import FermionicGaussianState, SlaterDeterminant
 from .hartree_fock import HartreeFock
 from .vscf import VSCF
 
-__all__ = ["HartreeFock", "VSCF"]
+__all__ = ["FermionicGaussianState", "HartreeFock", "SlaterDeterminant", "VSCF"]