set up sphinx docs

docs/Makefile

+# Minimal makefile for Sphinx documentation
+#
+
+# You can set these variables from the command line, and also
+# from the environment for the first two.
+SPHINXOPTS    ?=
+SPHINXBUILD   ?= sphinx-build
+SOURCEDIR     = source
+BUILDDIR      = build
+
+# Put it first so that "make" without argument is like "make help".
+help:
+	@$(SPHINXBUILD) -M help "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)
+
+.PHONY: help Makefile
+
+# Catch-all target: route all unknown targets to Sphinx using the new
+# "make mode" option.  $(O) is meant as a shortcut for $(SPHINXOPTS).
+%: Makefile
+	@$(SPHINXBUILD) -M $@ "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)

docs/environment.yml

+name: pymf-docs
+
+channels:
+  - conda-forge
+
+dependencies:
+  - python=3.11
+  - kwant
+  - myst-nb
+  - sympy
+  - numpy
+  - scipy
+  - matplotlib-base
+  - sphinx-togglebutton
+  - sphinx-copybutton
+  - pip
+  - git
+  - make
+  - pip:
+    - sphinx-book-theme>=1.1.0
+    - sphinx-tippy
+    - ..

docs/make.bat

+@ECHO OFF
+
+pushd %~dp0
+
+REM Command file for Sphinx documentation
+
+if "%SPHINXBUILD%" == "" (
+	set SPHINXBUILD=sphinx-build
+)
+set SOURCEDIR=source
+set BUILDDIR=build
+
+if "%1" == "" goto help
+
+%SPHINXBUILD% >NUL 2>NUL
+if errorlevel 9009 (
+	echo.
+	echo.The 'sphinx-build' command was not found. Make sure you have Sphinx
+	echo.installed, then set the SPHINXBUILD environment variable to point
+	echo.to the full path of the 'sphinx-build' executable. Alternatively you
+	echo.may add the Sphinx directory to PATH.
+	echo.
+	echo.If you don't have Sphinx installed, grab it from
+	echo.https://www.sphinx-doc.org/
+	exit /b 1
+)
+
+%SPHINXBUILD% -M %1 %SOURCEDIR% %BUILDDIR% %SPHINXOPTS% %O%
+goto end
+
+:help
+%SPHINXBUILD% -M help %SOURCEDIR% %BUILDDIR% %SPHINXOPTS% %O%
+
+:end
+popd

docs/source/conf.py

+# Configuration file for the Sphinx documentation builder.
+#
+# This file only contains a selection of the most common options. For a full
+# list see the documentation:
+# https://www.sphinx-doc.org/en/master/usage/configuration.html
+
+# -- Path setup --------------------------------------------------------------
+
+# If extensions (or modules to document with autodoc) are in another directory,
+# add these directories to sys.path here. If the directory is relative to the
+# documentation root, use os.path.abspath to make it absolute, like shown here.
+#
+import os
+import sys
+
+import pymf  # noqa: F401
+
+package_path = os.path.abspath("../pymf")
+# Suppress superfluous frozen modules warning.
+os.environ["PYDEVD_DISABLE_FILE_VALIDATION"] = "1"
+sys.path.insert(0, package_path)
+
+
+# -- Project information -----------------------------------------------------
+
+project = "pymf"
+copyright = "2024, pymf developers"
+author = "pymf developers"
+gitlab_url = "https://gitlab.kwant-project.org/qt/pymf"
+
+# The full version, including alpha/beta/rc tags
+release = pymf.__version__
+major, minor = pymf.__version_tuple__[:2]
+version = f"{major}.{minor}"
+
+# -- General configuration ---------------------------------------------------
+
+# Add any Sphinx extension module names here, as strings. They can be
+# extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
+# ones.
+extensions = [
+    "sphinx.ext.napoleon",
+    "sphinx.ext.autodoc",
+    "sphinx.ext.autosummary",
+    "sphinx.ext.mathjax",
+    "sphinx.ext.viewcode",
+    "sphinx.ext.intersphinx",
+    "myst_nb",
+    "sphinx_togglebutton",
+    "sphinx_copybutton",
+    "sphinx_tippy",
+]
+myst_enable_extensions = [
+    "dollarmath",
+    "amsmath",
+    "substitution",
+    "colon_fence",
+]
+nb_execution_timeout = 120
+nb_execution_raise_on_error = True
+autodoc_typehints = "description"
+autodoc_typehints_format = "short"
+
+intersphinx_mapping = {
+    "python": ("https://docs.python.org/3", None),
+    "kwant": ("https://kwant-project.org/doc/1", None),
+    "numpy": ("https://numpy.org/doc/stable/", None),
+    "scipy": ("https://docs.scipy.org/doc/scipy/", None),
+    "sympy": ("https://docs.sympy.org/latest/", None),
+}
+
+default_role = "autolink"
+
+# Add any paths that contain templates here, relative to this directory.
+templates_path = ["_templates"]
+
+# List of patterns, relative to source directory, that match files and
+# directories to ignore when looking for source files.
+# This pattern also affects html_static_path and html_extra_path.
+exclude_patterns = []
+
+autoclass_content = "both"
+# -- Options for HTML output -------------------------------------------------
+
+# The theme to use for HTML and HTML Help pages.  See the documentation for
+# a list of builtin themes.
+#
+html_theme = "sphinx_book_theme"
+
+html_theme_options = {
+    "repository_url": "https://gitlab.kwant-project.org/qt/kwant-scf",
+    "use_repository_button": True,
+    "use_issues_button": True,
+    "use_edit_page_button": True,
+    "path_to_docs": "docs/source",
+    "repository_branch": "main",
+    "use_download_button": True,
+    "home_page_in_toc": True,
+    # "logo": {
+    #     "image_light": "_static/logo.svg",
+    #     "image_dark": "_static/logo_dark.svg",
+    # },
+    "extra_footer": (
+        '<hr><div id="matomo-opt-out"></div>'
+        '<script src="https://piwik.kwant-project.org/index.php?'
+        "module=CoreAdminHome&action=optOutJS&divId=matomo-opt-out"
+        '&language=auto&showIntro=1"></script>'
+    ),
+}
+
+
+# Add any paths that contain custom static files (such as style sheets) here,
+# relative to this directory. They are copied after the builtin static files,
+# so a file named "default.css" will overwrite the builtin "default.css".
+# html_static_path = ["_static"]
+# html_css_files = ["local.css"]

docs/source/index.md

+---
+jupytext:
+  text_representation:
+    extension: .md
+    format_name: myst
+    format_version: 0.13
+    jupytext_version: 1.14.4
+kernelspec:
+  display_name: Python 3 (ipykernel)
+  language: python
+  name: python3
+---
+
+# pymf
+
+```{toctree}
+:hidden:
+:maxdepth: 1
+:caption: Tutorials
+
+mf_notes.md
+```
+
+## What is pymf?
+
+## Why pymf?
+
+## How does pymf work?
+
+## What does pymf not do yet?
+
+## Installation
+
+```bash
+pip install .
+```
+## Citing
+
+## Contributing
\ No newline at end of file

docs/source/mf_notes.md

+# Self-consistent mean field algorithm
+
+## Mean-field approximation
+
+The full hamiltonian is:
+
+$$
+\hat{H} = \hat{H_0} + \hat{V} = \sum_{ij} h_{ij} c^\dagger_{i} c_{j} + \frac{1}{2} \sum_{ijkl} v_{ijkl} c_i^\dagger c_j^\dagger c_l c_k
+$$
+
+We assume the dominant part of the ground state wavefunction comes from $\hat{H}_0$. Let's assume $b_i$ operators diagonalize the unperturbed hamiltonian:
+
+$$
+c_i^\dagger = \sum_{k} U_{ik} b_k^\dagger,
+$$
+
+such that the unperturbed groundstate wavefunction is:
+
+$$
+| 0 \rangle = \Pi_{E_i \leq \mu } b_i^\dagger |\textrm{vac}\rangle.
+$$
+
+Based on this definition, we define the normal ordering operator $:ABC...:$ such that it fulfills:
+
+$$
+:ABC...: | 0 \rangle = 0
+$$
+
+which practically means it orders $b_i$ operators based on whether its above or below the Fermi level $\mu$. 
+
+Under this definition of normal ordering, we define the Wick's expansion of the interaction term:
+
+$$
+\begin{multline}
+c_i^\dagger c_j^\dagger c_l c_k = :c_i^\dagger c_j^\dagger c_l c_k: \\+  \overline{c_i^\dagger c_j^\dagger} :c_l c_k: + \overline{c_i^\dagger c_k} :c_j^\dagger c_l: - \overline{c_i^\dagger c_l} :c_j^\dagger c_k: + \overline{c_l c_k} :c_i^\dagger c_j^\dagger: - \overline{c_j^\dagger c_k} :c_i^\dagger c_l: + \overline{c_j^\dagger c_l} :c_i^\dagger c_k: \\
+\overline{c_i^\dagger c_j^\dagger} \overline{c_l c_k} - \overline{c_i^\dagger c_l} \overline{c_j^\dagger c_k} + \overline{c_i^\dagger c_k} \overline{c_j^\dagger c_l}
+\end{multline}
+$$
+
+where the overline defines Wick's contraction:
+
+$$
+\overline{AB} = AB - :AB:.
+$$
+
+The expectation value of the interaction with respect to the $| 0 \rangle$ is:
+
+$$
+\langle 0 | c_i^\dagger c_j^\dagger c_l c_k | 0 \rangle = \langle 0 | \overline{c_i^\dagger c_j^\dagger} \overline{c_l c_k} - \overline{c_i^\dagger c_l} \overline{c_j^\dagger c_k} + \overline{c_i^\dagger c_k} \overline{c_j^\dagger c_l}  | 0 \rangle
+$$
+
+where we can forget about all the normal ordered states since those give zero acting on the unperturbed groundstate. To evaluate this further, we utilize the mean-field approximation:
+
+$$
+A B \approx \langle A \rangle B + A \langle B \rangle - \langle A \rangle \langle B \rangle 
+$$
+
+onto the contractions such that we get:
+
+$$
+\langle  c_i^\dagger c_j^\dagger c_l c_k \rangle \approx \langle c_i^\dagger c_j^\dagger \rangle \langle  c_l c_k \rangle + \langle c_i^\dagger c_k \rangle  \langle c_j^\dagger c_l \rangle - \langle c_i^\dagger c_l \rangle \langle c_j^\dagger c_k \rangle 
+$$
+
+note $\langle A B \rangle \approx \langle A \rangle  \langle B \rangle$ assuming mean-field. 
+
+To consider excitations from the groundstate, we make use of the mean-field approximation defined above:
+
+$$
+\begin{multline}
+c_i^\dagger c_j^\dagger c_l c_k \approx \\
+\langle c_i^\dagger c_j^\dagger \rangle c_l c_k + \langle c_i^\dagger c_k \rangle c_j^\dagger c_l - \langle c_i^\dagger c_l \rangle c_j^\dagger c_k + \langle c_l c_k \rangle c_i^\dagger c_j^\dagger - \langle c_j^\dagger c_k \rangle c_i^\dagger c_l + \langle c_j^\dagger c_l \rangle c_i^\dagger c_k + \\
+\langle c_i^\dagger c_j^\dagger \rangle \langle  c_l c_k \rangle + \langle c_i^\dagger c_k \rangle  \langle c_j^\dagger c_l \rangle - \langle c_i^\dagger c_l \rangle \langle c_j^\dagger c_k \rangle 
+\end{multline}
+$$
+
+Where we made use of the following operations:
+
+$$
+:c_i^\dagger c_j^\dagger c_l c_k: \approx 0
+$$
+
+$$
+\overline{c_i^\dagger c_k} \overline{c_j^\dagger c_l} \approx \langle \overline{c_i^\dagger c_k} \rangle \overline{c_j^\dagger c_l} + \overline{c_i^\dagger c_k} \langle \overline{c_j^\dagger c_l} \rangle - \langle \overline{c_i^\dagger c_k} \rangle \langle \overline{c_j^\dagger c_i} \rangle =  \langle c_i^\dagger c_k \rangle \overline{c_j^\dagger c_l} + \overline{c_i^\dagger c_k} \langle c_j^\dagger c_l \rangle - \langle c_i^\dagger c_k \rangle \langle c_j^\dagger c_l \rangle 
+$$
+
+$$
+\overline{c_i^\dagger c_k} :c_j^\dagger c_l: \approx \langle \overline{c_i^\dagger c_k} \rangle  :c_j^\dagger c_l: +  \overline{c_i^\dagger c_k} \langle :c_j^\dagger c_l: \rangle - \langle \overline{c_i^\dagger c_k} \rangle \langle :c_j^\dagger c_l: \rangle = \langle \overline{c_i^\dagger c_k} \rangle  :c_j^\dagger c_l: 
+$$
+
+
+$$
+\langle \overline{c_i^\dagger c_k} \rangle  = \langle c_i^\dagger c_k - :c_i^\dagger c_k: \rangle  = \langle c_i^\dagger c_k \rangle
+$$
+
+
+Without any superconducting terms, the form simplifies to:
+
+$$
+\begin{multline}
+c_i^\dagger c_j^\dagger c_l c_k \approx
+\langle c_i^\dagger c_k \rangle c_j^\dagger c_l - \langle c_i^\dagger c_l \rangle c_j^\dagger c_k - \langle c_j^\dagger c_k \rangle c_i^\dagger c_l + \langle c_j^\dagger c_l \rangle c_i^\dagger c_k + \\
+\langle c_i^\dagger c_k \rangle  \langle c_j^\dagger c_l \rangle - \langle c_i^\dagger c_l \rangle \langle c_j^\dagger c_k \rangle 
+\end{multline}
+$$
+
+## Finite size
+
+### Coulomb interaction
+
+We simplify the interaction term through the MF approximation to get:
+
+$$
+V = \frac{1}{2}\sum_{ijkl} v_{ijkl} c_i^{\dagger} c_j^{\dagger} c_l c_k
+\approx
+\frac12 \sum_{ijkl} v_{ijkl} \left[ \langle c_i^{\dagger} c_k \rangle c_j^{\dagger} c_l - \langle c_j^{\dagger} c_k \rangle c_i^{\dagger} c_l - \langle c_i^{\dagger} c_l \rangle c_j^{\dagger} c_k + \langle c_j^{\dagger} c_l \rangle c_i^{\dagger} c_k \right]
+$$
+(assuming no superconductivity)
+
+and an additional constant part:
+
+$$
+V_0 =  \frac{1}{2} \sum_{ijkl} v_{ijkl} \left(\langle c_j^{\dagger} c_l \rangle \langle c_i^{\dagger} c_k \rangle - \langle c_j^{\dagger} c_k \rangle \langle c_i^{\dagger} c_l \rangle \right).
+$$
+
+The interaction reads:
+
+$$
+v_{ijkl} = \iint w_{i}^*(r) w_{j}^*(r') V(r, r') w_{k}(r) w_l(r') dr dr' = \\
+\iint  V(|r - r'|) w_{i}^*(r)w_{k}(r) w_{j}^*(r')  w_l(r') dr dr' 
+$$
+
+whereas $w_i$ is a wannier function on site i (and corresponding dof). Whenever one interchanges $i \to j, k \to l$, the Coulomb term is preserved $v_{ijkl} = v_{jilk}$
+
+To make things more understandable, we are also going to explicitly split up position and spin indices: $i \to i \times \sigma$. In this notation, the Coulomb integral reads:
+
+$$
+v_{ijkl}^{\sigma_i \sigma_j \sigma_k \sigma_l} = 
+\iint V(|r - r'|) w_{i\times\sigma_i}^{*} (r)w_{k \times \sigma_k}(r) w_{j \times \sigma_j}^{*}(r')  w_{l\times \sigma_l}(r') dr dr' \delta_{\sigma_i \sigma_k} \delta_{\sigma_{j} \sigma_l}
+$$
+
+On a fine tight-binding model, we have:
+
+$$
+v_{ijkl}^{\sigma_i \sigma_j \sigma_k \sigma_l} = v_{ij} \delta_{ik} \delta_{jl} \delta_{\sigma_i \sigma_k} \delta_{\sigma_j \sigma_l}
+$$
+
+where $v_{ij} = V(r_i, r_j)$.
+
+We shall re-define $i$ index to absorb spin:
+
+$$
+\delta_{ik} \times \delta_{\sigma_{i} \sigma_{k}} \to \delta_{ik} 
+$$
+
+in this notation the above reads:
+
+$$
+v_{ijkl} = v_{ij} \delta_{ik} \delta_{jl}
+$$
+
+The mean-field terms are:
+
+$$
+\langle c_i^{\dagger} c_j\rangle = \langle \Psi_F|c_i^{\dagger} c_j | \Psi_F \rangle
+$$
+
+whereas $|\Psi_F \rangle = \Pi_{i=0}^{N_F} b_i^\dagger |0\rangle$. To make sense of things, we need to transform between $c_i$ basis (position + internal dof basis) into the $b_i$ basis (eigenfunction of a given mean-field Hamiltonian):
+
+$$
+c_i^\dagger = \sum_{k} U_{ik} b_k^\dagger
+$$
+
+where 
+
+$$
+U_{ik} = \langle{i|\psi_k} \rangle.
+$$
+
+That gives us:
+
+
+$$
+c_i^{\dagger} c_j = \sum_{k, l} U_{ik} U_{lj}^* b_k^\dagger b_{l}
+$$
+
+and its expectation value gives us the mean-field ... field $F_{ij}$:
+
+$$
+F_{ij} = \langle c_i^{\dagger} c_j\rangle =  \sum_{k, l} U_{ik} U_{lj}^* \langle \Psi_F| b_k^\dagger b_{l}| \Psi_F \rangle =  \sum_{k} U_{ik} U_{kj}^{*}
+$$
+
+whereas I assumed the indices for wavefunctions $k,l$ are ordered in terms of increasing eigenvalue. We pop that into the definition of the mean-field correction $V$:
+
+
+$$
+\begin{multline}
+V_{nm} = \frac12 \sum_{ijkl} v_{ijkl} \langle n| \left[ \langle c_i^{\dagger} c_k \rangle c_j^{\dagger} c_l - \langle c_j^{\dagger} c_k \rangle c_i^{\dagger} c_l - \langle c_i^{\dagger} c_l \rangle c_j^{\dagger} c_k + \langle c_j^{\dagger} c_l \rangle c_i^{\dagger} c_k \right] |m\rangle = \\
+ \frac12 \sum_{ijkl} v_{ijkl} \left[ +\delta_{jn}\delta_{lm} F_{ik} -\delta_{in}\delta_{lm} F_{jk} -\delta_{jn}\delta_{km} F_{il} + \delta_{in}\delta_{km} F_{jl} \right] = \\
+\frac12 \left[ \sum_{ik} v_{inkm} F_{ik} - \sum_{jk} v_{njkm} F_{jk} - \sum_{il} v_{inml} F_{il} + \sum_{jl} v_{njml} F_{jl} \right] = \\
+-\sum_{ij} F_{ij} \left(v_{inmj} - v_{injm} \right)
+\end{multline}
+$$
+
+where I used the $v_{ijkl} = v_{jilk}$ symmetry from Coulomb.
+
+For a tight-binding grid, the mean-field correction simplifies to:
+
+$$
+\begin{multline}
+V_{nm} = - \sum_{ij} F_{ij} \left(v_{inmj} - v_{injm} \right) = \\
+-\sum_{ij}F_{ij} v_{in} \delta_{im} \delta_{nj} + \sum_{ij}F_{ij} v_{in} \delta_{ij} \delta_{nm} = \\
+-F_{mn} v_{mn} + \sum_{i} F_{ii} v_{in} \delta_{nm}
+\end{multline}
+$$
+
+the first term is the exchange interaction whereas the second one is the direct interaction.
+
+Similarly, the constant offset term reads:
+
+$$
+\begin{multline}
+V_0 = \frac{1}{2} \sum_{ijkl} v_{ijkl} \left(F_{jl} F_{ik} - F_{jk} F_{il} \right) = \\
+\frac{1}{2} \sum_{ijkl} v_{ij} \delta_{ik} \delta_{jl} \left(F_{jl} F_{ik} - F_{jk} F_{il}\right) \\
+= \frac{1}{2} \sum_{ij} v_{ij} \left(F_{ii} F_{jj} - F_{ji} F_{ij}\right)
+\end{multline}
+$$
+
+where we identify the first term as the exchange (mixes indices) and the right one as the direct (diagonal in indicies).
+
+## Translational Invariance
+
+The above assumed a finite tight-binding model - all $nm$-indices contain the position of all atoms (among other dof). In this section tho we want to consider an infinite system with translational invariance.
+
+To begin with we deconstruct a general matrix $O_{nm}$ into the cell degrees of freedom ($nm$) and the position of the the cell itself ($ij$):
+
+$$
+O_{nm} \to O^{ij}_{nm}
+$$
+
+and we will Fourier transform the upper indices into k-space:
+
+$$
+O_{mn}(k) = \sum_{ij} O_{nm}^{ij} e^{-i k (R_i-R_j)} 
+$$
+
+where I assumed $O$ (and thus all operators I will consider here) is local and thus diagonal in k-space.
+
+Now lets rewrite our main result in the previous section using our new notation:
+
+$$
+V_{nm}^{ij} =-F_{mn}^{ij} v_{mn}^{ij} + \sum_{r,p} F_{pp}^{rr} v_{pn}^{rj} \delta_{nm} \delta^{ij}
+$$
+
+Lets first consider the second (direct) term. Lets express the corresponding $F$ term in k-space:
+
+$$
+F_{pp}^{rr} = \int e^{i k (R_r-R_r)} F_{pp}(k) dk = \int F_{pp}(k) dk 
+$$
+
+Notice that in the final expression, there is no $rr$ dependence and thus this term is cell-periodic. Therefore, we shall redefine it as cell electron density $\rho$:
+$$
+F_{pp}^0 = F_{pp}(R = 0) = \int F_{pp}(k) dk 
+$$
+
+Now since $\rho$ has no $r$ dependence, we can proceed with the sum:
+
+$$
+\sum_{r} v_{pn}^{rj} = \int v_{pn}(k) e^{ik R_j} \sum_{r} e^{-i k R_r} dk = \int v_{pn}(k) e^{ik R_j} \delta_{k, 0} dk = v_{pn}(0)
+$$
+
+We are finally ready to Fourier transform the main result. Invoking convolution theorem and the results above gives us:
+
+$$
+V_{nm}(k) = \sum_{p} F_{pp}^0 v_{pn}(0) \delta_{nm} -F_{mn}(k) \circledast v_{mn}(k) = V_n^D - F_{mn}(k) \circledast v_{mn}(k) 
+$$
+
+which does make sense. The first term (direct) is a potential term coming from the mean-field and the second term (exchange) is purely responsible for the hopping.
+
+The constant offset is:
+$$
+V_0 = \frac{1}{2} \sum_{r,s} \rho_r v_{rs}(0) \rho_s- \\ \frac{1}{2} tr\left[\int_{BZ} \left(F \circledast v\right)(k) F(k) dk \right]
+$$
+
+## Short-Range interactions
+
+In the case of short-range interactions, it is much more convenient to go back to real space to both store objects and perform the operations. In real space the mean-field part of the Hamiltonian reads:
+
+$$
+V_{nm}(\mathbf{R}) = V_n^D \delta(\mathbf{R}) - F_{mn}(\mathbf{R}) v_{mn}(\mathbf{R})
+$$
+
+(the first term might need some prefactor from Fourier transformation)
+
+where $\mathbf{R}$ is a sequence of integers representing real-space unit cell indices.
+
+### Proposed Algorithm
+Given an initial Hamiltonian $H_0 (R)$ and the interaction term $v(R)$ in real-space, the mean-field algorithm is the following:
+
+0. Start with a mean-field guess in real-space: $V(R)$.
+1. Fourier transform tight-binding model and the mean-field in real space to a given k-grid: $H_0(R) + V(R) \to H_0(k) + V(k)$
+2. Diagonalize and evaluate the density matrix: $H_0(k) + V(k) \to F(k)$
+3. Fourier transform the density matrix back to real-space: $F(k) \to F(R)$
+4. Evaluate the new mean-field Hamiltonian $V(R)$ according to the equation above.
+5. Evaluate self-consistency metric (could be based either on $V(R/k)$ or $F(R/k)$). Based on that, either stop or go back to 1 with a modified $V(R)$ starting guess.

pymf/__init__.py

+"Mean-field tight-binding solver"
+
+try:
+    from ._version import __version__, __version_tuple__
+except ImportError:
+    __version__ = "unknown"
+    __version_tuple__ = (0, 0, "unknown", "unknown")
+
+from .mf import density_matrix
+
+__all__ = [
+    "density_matrix",
+    "__version__",
+    "__version_tuple__",
+]