minor update

k-tamuraphys · Oct 27, 2021 · 652ad04 · 652ad04
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Showing 6 changed files with 52 additions and 16 deletions.
diff --git a/qiskit_nature/problems/second_quantization/lattice/lattice/__init__.py b/qiskit_nature/problems/second_quantization/lattice/lattice/__init__.py
@@ -10,7 +10,7 @@
 # copyright notice, and modified files need to carry a notice indicating
 # that they have been altered from the originals.
 
-"""Lattice"""
+"""A class containing information about the Lattice."""
 from .hyper_cubic_lattice import HyperCubicLattice
 from .lattice import Lattice
 from .line_lattice import LineLattice

diff --git a/qiskit_nature/problems/second_quantization/lattice/lattice/hyper_cubic_lattice.py b/qiskit_nature/problems/second_quantization/lattice/lattice/hyper_cubic_lattice.py
@@ -22,7 +22,26 @@
 
 
 class HyperCubicLattice(Lattice):
-    """Hyper-cubic lattice in d dimension."""
+    """Hyper-cubic lattice in d dimension.
+
+    The :class:`HyperCubicLattice` can be initialized with
+    tuples of `size`, `edge_parameters`, and `boundary_conditions`.
+    For example,
+
+    .. jupyter-execute::
+
+        from qiskit_nature.problems.second_quantization.lattice import HyperCubicLattice
+
+        lattice = HyperCubicLattice(
+            size = (3, 4, 5),
+            edge_parameter = (1.0, -2.0, 3.0),
+            onsite_parameter = 2.0,
+            boundary_condition = ("open", "open", "open")
+
+    is a three-dimensional lattice of size 3 by 4 by 5, which has weights 1.0, -2.0, 3.0 on edges
+    in x, y, and z directions, respectively, and weights 2.0 on self-loops.
+    The boundary conditions are "open" for all the directions.
+    """
 
     def __init__(
         self,
@@ -34,11 +53,17 @@ def __init__(
         """
         Args:
             size: Lengths of each dimension.
-            edge_parameter: Weights on the unit edges. Defaults to 1.0.
+            edge_parameter: Weights on the edges in each direction.
+                When it is a single value, it is interpreted as a tuple of the same length as `size`
+                consisting of the same values.
+                Defaults to 1.0.
             onsite_parameter: Weight on the self-loops, which are edges connecting a node to itself.
+                This is uniform over the lattice points.
                 Defaults to 0.0.
             boundary_condition: Boundary condition for each dimension.
                 The available boundary conditions are: "open", "periodic".
+                When it is a single value, it is interpreted as a tuple of the same length as `size`
+                consisting of the same values.
                 Defaults to "open".
 
         Raises:
@@ -100,8 +125,8 @@ def __init__(
         self.boundary_edges = []
         for i in range(self.dim):
             # add edges when the boundary condition is periodic.
-            # The periodic boundary condition in the i-th direction.
-            # It makes sense only when size[i] is greater than 2.
+            # when the boundary condition in the i-th direction is periodic,
+            # it makes sense only when size[i] is greater than 2.
             if boundary_condition[i] == "periodic":
                 if size[i] <= 2:
                     continue

diff --git a/qiskit_nature/problems/second_quantization/lattice/lattice/line_lattice.py b/qiskit_nature/problems/second_quantization/lattice/lattice/line_lattice.py
@@ -10,7 +10,7 @@
 # copyright notice, and modified files need to carry a notice indicating
 # that they have been altered from the originals.
 
-"""Line lattice"""
+"""The line lattice"""
 from .hyper_cubic_lattice import HyperCubicLattice
 
 
@@ -31,7 +31,7 @@ def __init__(
             onsite_parameter: Weight on the self-loops, which are edges connecting a node to itself.
                 Defaults to 0.0.
             boundary_condition: Boundary condition.
-                Boundary condition must be specified by "open" or "periodic".
+                The available boundary conditions are: "open", "periodic".
                 Defaults to "open".
         """
 

diff --git a/qiskit_nature/problems/second_quantization/lattice/lattice/square_lattice.py b/qiskit_nature/problems/second_quantization/lattice/lattice/square_lattice.py
@@ -10,7 +10,7 @@
 # copyright notice, and modified files need to carry a notice indicating
 # that they have been altered from the originals.
 
-"""Square lattice"""
+"""The square lattice"""
 from typing import Tuple, Union
 
 from .hyper_cubic_lattice import HyperCubicLattice
@@ -31,11 +31,16 @@ def __init__(
         Args:
             rows: Length of the x direction.
             cols: Length of the y direction.
-            edge_parameter: Weights on the unit edges. Defaults to 1.0.
+            edge_parameter: Weights on the edges in x and y direction.
+                When it is a single value, it is interpreted as a tuple of length 2
+                consisting of the same values.
+                Defaults to 1.0.
             onsite_parameter: Weight on the self-loops, which are edges connecting a node to itself.
                 Defaults to 0.0.
             boundary_condition: Boundary condition for each direction.
-                Boundary condition must be specified by "open" or "periodic".
+                The available boundary conditions are: "open", "periodic".
+                When it is a single value, it is interpreted as a tuple of length 2
+                consisting of the same values.
                 Defaults to "open".
         """
         self.rows = rows

diff --git a/qiskit_nature/problems/second_quantization/lattice/lattice/triangular_lattice.py b/qiskit_nature/problems/second_quantization/lattice/lattice/triangular_lattice.py
@@ -10,7 +10,7 @@
 # copyright notice, and modified files need to carry a notice indicating
 # that they have been altered from the originals.
 
-"""Triangular lattice"""
+"""The triangular lattice"""
 from itertools import product
 from math import pi
 from typing import Callable, List, Optional, Tuple, Union
@@ -36,12 +36,17 @@ def __init__(
         Args:
             rows: Length of the x direction.
             cols: Length of the y direction.
-            edge_parameter: Weights on the unit edges.
-                This is specified as a tuple of length 3 or a single number.Defaults to 1.0,
+            edge_parameter: Weights on the edges in x, y and diagonal directions.
+                This is specified as a tuple of length 3 or a single value.
+                When it is a single value, it is interpreted as a tuple of length 3
+                consisting of the same values.
+                Defaults to 1.0,
             onsite_parameter: Weight on the self-loops, which are edges connecting a node to itself.
                 Defaults to 0.0.
             boundary_condition: Boundary condition for each direction.
-                Boundary condition must be specified by "open" or "periodic".
+                The available boundary conditions are: "open", "periodic".
+                When it is a single value, it is interpreted as a tuple of length 3
+                consisting of the same values.
                 Defaults to "open".
 
         Raises:

diff --git a/qiskit_nature/problems/second_quantization/lattice/models/fermi_hubbard_model.py b/qiskit_nature/problems/second_quantization/lattice/models/fermi_hubbard_model.py
@@ -89,10 +89,11 @@ def from_parameters(
 
         Returns:
             FermiHubbardModel: The Fermi-Hubbard model generated
-                                from the given hopping matrix and on-site interaction.
+                from the given hopping matrix and on-site interaction.
 
         Raises:
-            ValueError: If the shape of the hopping matrix is invalid.
+            ValueError: If the hopping matrix is not square matrix,
+                it is invalid.
         """
         # make a graph from the hopping matrix.
         # This should be replaced by from_adjacency_matrix of retworkx.