{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "# Creating structures in pyiron" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "This section gives a brief introduction about some of the tools available in pyiron to construct atomic structures. " ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "For the sake of compatibility, our structure class is written to be compatible with the popular Atomistic Simulation Environment package ([ASE](https://wiki.fysik.dtu.dk/ase/)). This makes it possible to use routines from ASE to help set-up structures.\n", "\n", "Furthermore, pyiron uses the [NGLview](http://nglviewer.org/nglview/latest/api.html) package to visualize the structures and trajectories interactively in 3D using NGLview-widgets." ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "As preparation for the following discussion we import a few python libraries" ] }, { "cell_type": "code", "execution_count": 1, "metadata": { "ExecuteTime": { "end_time": "2018-02-10T08:32:28.838135Z", "start_time": "2018-02-10T08:32:26.787708Z" } }, "outputs": [], "source": [ "import numpy as np\n", "%matplotlib inline\n", "import matplotlib.pylab as plt" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "and create a pyiron project named 'structures':" ] }, { "cell_type": "code", "execution_count": 2, "metadata": {}, "outputs": [], "source": [ "from pyiron.project import Project\n", "pr = Project(path='structures')" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Bulk crystals" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "In this section we discuss various possibilities to create bulk crystal structures." ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "### Using `create_structure()`" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "The simplest way to generate simple crystal structures is using the inbuilt `create_structure()` function specifying the element symbol, Bravais basis and the lattice constant(s)\n", "\n", "Note: The output gives a cubic cell rather than the smallest non-orthogonal unit cell." ] }, { "cell_type": "code", "execution_count": 3, "metadata": { "ExecuteTime": { "end_time": "2018-02-10T08:36:09.587677Z", "start_time": "2018-02-10T08:36:08.971155Z" } }, "outputs": [], "source": [ "structure = pr.create_structure('Al', \n", " bravais_basis='fcc', \n", " lattice_constant=4.05)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "To plot the structure interactively in 3D simply use:" ] }, { "cell_type": "code", "execution_count": 4, "metadata": {}, "outputs": [ { "data": { "application/vnd.jupyter.widget-view+json": { "model_id": "8e422abb3d8240a890a1c29128f4eef0", "version_major": 2, "version_minor": 0 }, "text/html": [ "

Failed to display Jupyter Widget of type NGLWidget.

\n", "

\n", " If you're reading this message in the Jupyter Notebook or JupyterLab Notebook, it may mean\n", " that the widgets JavaScript is still loading. If this message persists, it\n", " likely means that the widgets JavaScript library is either not installed or\n", " not enabled. See the Jupyter\n", " Widgets Documentation for setup instructions.\n", "

\n", "

\n", " If you're reading this message in another frontend (for example, a static\n", " rendering on GitHub or NBViewer),\n", " it may mean that your frontend doesn't currently support widgets.\n", "

\n" ], "text/plain": [ "NGLWidget()" ] }, "metadata": {}, "output_type": "display_data" } ], "source": [ "structure.plot3d()" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "### Using `create_ase_bulk()`\n", "\n", "Another convenient way to set up structures is using the `create_ase_bulk()` function which is built on top of the ASE build package for [bulk crystals](https://wiki.fysik.dtu.dk/ase/ase/build/build.html#ase.build.bulk). This function returns an object which is of the pyiron structure object type." ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "**Example:** fcc bulk aluminum in a cubic cell" ] }, { "cell_type": "code", "execution_count": 5, "metadata": { "ExecuteTime": { "end_time": "2018-02-11T08:48:16.795460Z", "start_time": "2018-02-11T08:48:16.525956Z" } }, "outputs": [ { "data": { "application/vnd.jupyter.widget-view+json": { "model_id": "75211415e1214cbc896dccdc3cd9a59d", "version_major": 2, "version_minor": 0 }, "text/html": [ "

Failed to display Jupyter Widget of type NGLWidget.

\n", "

\n", " If you're reading this message in the Jupyter Notebook or JupyterLab Notebook, it may mean\n", " that the widgets JavaScript is still loading. If this message persists, it\n", " likely means that the widgets JavaScript library is either not installed or\n", " not enabled. See the Jupyter\n", " Widgets Documentation for setup instructions.\n", "

\n", "

\n", " If you're reading this message in another frontend (for example, a static\n", " rendering on GitHub or NBViewer),\n", " it may mean that your frontend doesn't currently support widgets.\n", "

\n" ], "text/plain": [ "NGLWidget()" ] }, "metadata": {}, "output_type": "display_data" } ], "source": [ "structure = pr.create_ase_bulk('Al', cubic=True)\n", "structure.plot3d()" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "**Example:** wurtzite GaN in a 3x3x3 repeated orthorhombic cell.\n", "\n", "Note: \n", "- In contrast to new_structure = structure.repeat() which creates a new object, set_repeat() modifies the existing structure object.\n", "- Setting `spacefill=False` in the `plot3d()` method changes the atomic structure style to \"ball and stick\"." ] }, { "cell_type": "code", "execution_count": 6, "metadata": { "ExecuteTime": { "end_time": "2018-02-11T08:51:10.251891Z", "start_time": "2018-02-11T08:51:09.957494Z" } }, "outputs": [ { "data": { "application/vnd.jupyter.widget-view+json": { "model_id": "5c206f701b0b44c79125630172dcb00d", "version_major": 2, "version_minor": 0 }, "text/html": [ "

Failed to display Jupyter Widget of type NGLWidget.

\n", "

\n", " If you're reading this message in the Jupyter Notebook or JupyterLab Notebook, it may mean\n", " that the widgets JavaScript is still loading. If this message persists, it\n", " likely means that the widgets JavaScript library is either not installed or\n", " not enabled. See the Jupyter\n", " Widgets Documentation for setup instructions.\n", "

\n", "

\n", " If you're reading this message in another frontend (for example, a static\n", " rendering on GitHub or NBViewer),\n", " it may mean that your frontend doesn't currently support widgets.\n", "

\n" ], "text/plain": [ "NGLWidget()" ] }, "metadata": {}, "output_type": "display_data" } ], "source": [ "structure = pr.create_ase_bulk('AlN', \n", " crystalstructure='wurtzite', \n", " a=3.5, orthorhombic=True)\n", "structure.set_repeat([3,3,3])\n", "structure.plot3d(spacefill=False)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "### Using the ASE spacegroup class" ] }, { "cell_type": "code", "execution_count": 7, "metadata": { "ExecuteTime": { "end_time": "2018-02-11T09:37:06.542461Z", "start_time": "2018-02-11T09:37:06.310283Z" } }, "outputs": [], "source": [ "from ase.spacegroup import crystal\n", "from pyiron import ase_to_pyiron\n", "\n", "a = 9.04\n", "skutterudite = crystal(('Co', 'Sb'),\n", " basis=[(0.25, 0.25, 0.25), (0.0, 0.335, 0.158)],\n", " spacegroup=204,\n", " cellpar=[a, a, a, 90, 90, 90])\n", "skutterudite = ase_to_pyiron(skutterudite)" ] }, { "cell_type": "code", "execution_count": 8, "metadata": { "ExecuteTime": { "end_time": "2018-02-11T09:37:47.604586Z", "start_time": "2018-02-11T09:37:47.457434Z" } }, "outputs": [ { "data": { "application/vnd.jupyter.widget-view+json": { "model_id": "100537f489324535bb72cd03cb93d4a3", "version_major": 2, "version_minor": 0 }, "text/html": [ "

Failed to display Jupyter Widget of type NGLWidget.

\n", "

\n", " If you're reading this message in the Jupyter Notebook or JupyterLab Notebook, it may mean\n", " that the widgets JavaScript is still loading. If this message persists, it\n", " likely means that the widgets JavaScript library is either not installed or\n", " not enabled. See the Jupyter\n", " Widgets Documentation for setup instructions.\n", "

\n", "

\n", " If you're reading this message in another frontend (for example, a static\n", " rendering on GitHub or NBViewer),\n", " it may mean that your frontend doesn't currently support widgets.\n", "

\n" ], "text/plain": [ "NGLWidget()" ] }, "metadata": {}, "output_type": "display_data" } ], "source": [ "skutterudite.plot3d()" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Accessing the properties of the structure object" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "Using the bulk aluminum fcc example from before the structure object can be created by" ] }, { "cell_type": "code", "execution_count": 9, "metadata": {}, "outputs": [], "source": [ "structure = pr.create_ase_bulk('Al', cubic=True)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "A summary of the information about the structure is given by using" ] }, { "cell_type": "code", "execution_count": 10, "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Al: [ 0. 0. 0.]\n", "Al: [ 0. 2.025 2.025]\n", "Al: [ 2.025 0. 2.025]\n", "Al: [ 2.025 2.025 0. ]\n", "pbc: [ True True True]\n", "cell: \n", "[[ 4.05 0. 0. ]\n", " [ 0. 4.05 0. ]\n", " [ 0. 0. 4.05]]\n", "\n" ] } ], "source": [ "print(structure)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "The cell vectors of the structure object can be accessed and edited through" ] }, { "cell_type": "code", "execution_count": 11, "metadata": {}, "outputs": [ { "data": { "text/plain": [ "array([[ 4.05, 0. , 0. ],\n", " [ 0. , 4.05, 0. ],\n", " [ 0. , 0. , 4.05]])" ] }, "execution_count": 11, "metadata": {}, "output_type": "execute_result" } ], "source": [ "structure.cell" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "The positions of the atoms in the structure object can be accessed and edited through" ] }, { "cell_type": "code", "execution_count": 12, "metadata": {}, "outputs": [ { "data": { "text/plain": [ "array([[ 0. , 0. , 0. ],\n", " [ 0. , 2.025, 2.025],\n", " [ 2.025, 0. , 2.025],\n", " [ 2.025, 2.025, 0. ]])" ] }, "execution_count": 12, "metadata": {}, "output_type": "execute_result" } ], "source": [ "structure.positions" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Point defects" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "### Creating a single vacancy" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "We start by setting up a 4x4x4 supercell" ] }, { "cell_type": "code", "execution_count": 13, "metadata": { "ExecuteTime": { "end_time": "2018-02-12T09:07:41.713136Z", "start_time": "2018-02-12T09:07:41.358933Z" } }, "outputs": [], "source": [ "structure = pr.create_ase_bulk('Al', cubic=True)\n", "structure.set_repeat([4,4,4])" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "To create the vacancy at position index \"0\" simply use:" ] }, { "cell_type": "code", "execution_count": 14, "metadata": {}, "outputs": [], "source": [ "del structure[0]" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "To plot the structure that now contains a vacancy run:" ] }, { "cell_type": "code", "execution_count": 15, "metadata": {}, "outputs": [ { "data": { "application/vnd.jupyter.widget-view+json": { "model_id": "26c4b020823244529e04867780cd0c87", "version_major": 2, "version_minor": 0 }, "text/html": [ "

Failed to display Jupyter Widget of type NGLWidget.

\n", "

\n", " If you're reading this message in the Jupyter Notebook or JupyterLab Notebook, it may mean\n", " that the widgets JavaScript is still loading. If this message persists, it\n", " likely means that the widgets JavaScript library is either not installed or\n", " not enabled. See the Jupyter\n", " Widgets Documentation for setup instructions.\n", "

\n", "

\n", " If you're reading this message in another frontend (for example, a static\n", " rendering on GitHub or NBViewer),\n", " it may mean that your frontend doesn't currently support widgets.\n", "

\n" ], "text/plain": [ "NGLWidget()" ] }, "metadata": {}, "output_type": "display_data" } ], "source": [ "structure.plot3d()" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "### Creating multiple vacancies" ] }, { "cell_type": "code", "execution_count": 16, "metadata": { "ExecuteTime": { "end_time": "2018-02-12T09:17:37.707055Z", "start_time": "2018-02-12T09:17:37.321281Z" } }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Number of atoms in the repeat unit: 256\n" ] } ], "source": [ "# First create a 4x4x4 supercell\n", "structure = pr.create_ase_bulk('Al', cubic=True)\n", "structure.set_repeat([4,4,4])\n", "print('Number of atoms in the repeat unit: ',structure.get_number_of_atoms())" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "The `del` command works for passing a list of indices to the structure object. For example, a random set of n$_{\\text{vac}}$ vacancies can be created by using" ] }, { "cell_type": "code", "execution_count": 17, "metadata": {}, "outputs": [], "source": [ "# Generate a list of indices for the vacancies\n", "n_vac = 24\n", "vac_ind_lst = np.random.permutation(len(structure))[:n_vac]\n", "\n", "# Remove atoms according to the \"vac_ind_lst\"\n", "del structure[vac_ind_lst]" ] }, { "cell_type": "code", "execution_count": 18, "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Number of atoms in the repeat unit: 232\n" ] }, { "data": { "application/vnd.jupyter.widget-view+json": { "model_id": "2a9e0ea878794202939e28793b094034", "version_major": 2, "version_minor": 0 }, "text/html": [ "

Failed to display Jupyter Widget of type NGLWidget.

\n", "

\n", " If you're reading this message in the Jupyter Notebook or JupyterLab Notebook, it may mean\n", " that the widgets JavaScript is still loading. If this message persists, it\n", " likely means that the widgets JavaScript library is either not installed or\n", " not enabled. See the Jupyter\n", " Widgets Documentation for setup instructions.\n", "

\n", "

\n", " If you're reading this message in another frontend (for example, a static\n", " rendering on GitHub or NBViewer),\n", " it may mean that your frontend doesn't currently support widgets.\n", "

\n" ], "text/plain": [ "NGLWidget()" ] }, "metadata": {}, "output_type": "display_data" } ], "source": [ "# Visualize the structure\n", "print('Number of atoms in the repeat unit: ',structure.get_number_of_atoms())\n", "structure.plot3d()" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "### Random substitutial alloys" ] }, { "cell_type": "code", "execution_count": 19, "metadata": {}, "outputs": [], "source": [ "# Create a 4x4x4 supercell\n", "structure = pr.create_ase_bulk('Al', cubic=True)\n", "structure.set_repeat([4,4,4])" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "Substitutional atoms can be defined by changing the atomic species accessed through its position index.\n", "\n", "Here, we set $n_{\\text{sub}}$ magnesium substitutional atoms at random positions" ] }, { "cell_type": "code", "execution_count": 20, "metadata": { "ExecuteTime": { "end_time": "2018-02-12T09:19:45.031085Z", "start_time": "2018-02-12T09:19:44.598754Z" } }, "outputs": [], "source": [ "n_sub = 24\n", "structure[np.random.permutation(len(structure))[:n_sub]] = 'Mg'" ] }, { "cell_type": "code", "execution_count": 21, "metadata": {}, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "Number of atoms in the repeat unit: 256\n", "Chemical formula: Al232Mg24\n" ] }, { "data": { "application/vnd.jupyter.widget-view+json": { "model_id": "85fbfa50bf484de081f7dbd225cf52a6", "version_major": 2, "version_minor": 0 }, "text/html": [ "

Failed to display Jupyter Widget of type NGLWidget.

\n", "

\n", " If you're reading this message in the Jupyter Notebook or JupyterLab Notebook, it may mean\n", " that the widgets JavaScript is still loading. If this message persists, it\n", " likely means that the widgets JavaScript library is either not installed or\n", " not enabled. See the Jupyter\n", " Widgets Documentation for setup instructions.\n", "

\n", "

\n", " If you're reading this message in another frontend (for example, a static\n", " rendering on GitHub or NBViewer),\n", " it may mean that your frontend doesn't currently support widgets.\n", "

\n" ], "text/plain": [ "NGLWidget()" ] }, "metadata": {}, "output_type": "display_data" } ], "source": [ "# Visualize the structure and print some additional information about the structure\n", "print('Number of atoms in the repeat unit: ',structure.get_number_of_atoms())\n", "print('Chemical formula: ',structure.get_chemical_formula())\n", "structure.plot3d()" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Explicit definition of the structure\n", "\n", "You can also set-up structures through the explicit input of the cell parameters and positions" ] }, { "cell_type": "code", "execution_count": 22, "metadata": {}, "outputs": [ { "data": { "application/vnd.jupyter.widget-view+json": { "model_id": "530d3f040f5145efaa6f33410143439d", "version_major": 2, "version_minor": 0 }, "text/html": [ "

Failed to display Jupyter Widget of type NGLWidget.

\n", "

\n", " If you're reading this message in the Jupyter Notebook or JupyterLab Notebook, it may mean\n", " that the widgets JavaScript is still loading. If this message persists, it\n", " likely means that the widgets JavaScript library is either not installed or\n", " not enabled. See the Jupyter\n", " Widgets Documentation for setup instructions.\n", "

\n", "

\n", " If you're reading this message in another frontend (for example, a static\n", " rendering on GitHub or NBViewer),\n", " it may mean that your frontend doesn't currently support widgets.\n", "

\n" ], "text/plain": [ "NGLWidget()" ] }, "metadata": {}, "output_type": "display_data" } ], "source": [ "cell = 10.0 * np.eye(3) # Specifying the cell dimensions\n", "positions = [[0.25, 0.25, 0.25], [0.75, 0.75, 0.75]]\n", "elements = ['O', 'O']\n", "\n", "# Now use the Atoms class to create the instance.\n", "O_dimer = pr.create_atoms(elements=elements, scaled_positions=positions, cell=cell)\n", "\n", "O_dimer.plot3d()" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Surfaces (with ASE)\n", "\n", "Some more commonly studied surfaces can also be defined with the `create_surface()` function based on the [ASE surface builder](https://wiki.fysik.dtu.dk/ase/ase/build/surface.html)" ] }, { "cell_type": "code", "execution_count": 23, "metadata": {}, "outputs": [], "source": [ "fcc111 = pr.create_surface(\"Pt\", \n", " surface_type=\"fcc111\", \n", " size=(3, 4, 5), \n", " a=4.2, \n", " vacuum=20)" ] }, { "cell_type": "code", "execution_count": 24, "metadata": {}, "outputs": [ { "data": { "application/vnd.jupyter.widget-view+json": { "model_id": "9a19579b86fb4998a53351fa921ba039", "version_major": 2, "version_minor": 0 }, "text/html": [ "

Failed to display Jupyter Widget of type NGLWidget.

\n", "

\n", " If you're reading this message in the Jupyter Notebook or JupyterLab Notebook, it may mean\n", " that the widgets JavaScript is still loading. If this message persists, it\n", " likely means that the widgets JavaScript library is either not installed or\n", " not enabled. See the Jupyter\n", " Widgets Documentation for setup instructions.\n", "

\n", "

\n", " If you're reading this message in another frontend (for example, a static\n", " rendering on GitHub or NBViewer),\n", " it may mean that your frontend doesn't currently support widgets.\n", "

\n" ], "text/plain": [ "NGLWidget()" ] }, "metadata": {}, "output_type": "display_data" } ], "source": [ "fcc111.plot3d()" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Importing from cif/other file formats\n", "\n", "Parsers from ASE can be used to import structures from other formats. In this example, we will download and import a Nepheline structure from the [Crystallography Open Database (COD)](http://www.crystallography.net/cod/index.php)" ] }, { "cell_type": "code", "execution_count": 25, "metadata": {}, "outputs": [], "source": [ "# The COD structures can be accessed through their unique COD identifier\n", "filename = '1008753.cif'\n", "url = 'http://www.crystallography.net/cod/{}'.format(filename)" ] }, { "cell_type": "code", "execution_count": 26, "metadata": {}, "outputs": [], "source": [ "# Download and save the structure file locally\n", "import urllib\n", "urllib.request.urlretrieve(url=url, filename='strucs.'+filename);" ] }, { "cell_type": "code", "execution_count": 27, "metadata": {}, "outputs": [], "source": [ "# Using ase parsers to read the structure and then convert to a pyiron instance\n", "import ase\n", "from pyiron import ase_to_pyiron\n", "\n", "structure = ase_to_pyiron(ase.io.read(filename='strucs.'+filename,\n", " format='cif'))" ] }, { "cell_type": "code", "execution_count": 28, "metadata": {}, "outputs": [ { "data": { "application/vnd.jupyter.widget-view+json": { "model_id": "4c516697fd64490986f5d79fed1f555e", "version_major": 2, "version_minor": 0 }, "text/html": [ "

Failed to display Jupyter Widget of type NGLWidget.

\n", "

\n", " If you're reading this message in the Jupyter Notebook or JupyterLab Notebook, it may mean\n", " that the widgets JavaScript is still loading. If this message persists, it\n", " likely means that the widgets JavaScript library is either not installed or\n", " not enabled. See the Jupyter\n", " Widgets Documentation for setup instructions.\n", "

\n", "

\n", " If you're reading this message in another frontend (for example, a static\n", " rendering on GitHub or NBViewer),\n", " it may mean that your frontend doesn't currently support widgets.\n", "

\n" ], "text/plain": [ "NGLWidget()" ] }, "metadata": {}, "output_type": "display_data" } ], "source": [ "structure.plot3d()" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [] } ], "metadata": { "anaconda-cloud": {}, "kernelspec": { "display_name": "Python [default]", "language": "python", "name": "python3" }, "language_info": { "codemirror_mode": { "name": "ipython", "version": 3 }, "file_extension": ".py", "mimetype": "text/x-python", "name": "python", "nbconvert_exporter": "python", "pygments_lexer": "ipython3", "version": "3.5.4" }, "latex_envs": { "LaTeX_envs_menu_present": true, "autocomplete": true, "bibliofile": "biblio.bib", "cite_by": "apalike", "current_citInitial": 1, "eqLabelWithNumbers": true, "eqNumInitial": 1, "hotkeys": { "equation": "Ctrl-E", "itemize": "Ctrl-I" }, "labels_anchors": false, "latex_user_defs": false, "report_style_numbering": false, "user_envs_cfg": false }, "toc": { "nav_menu": {}, "number_sections": true, "sideBar": true, "skip_h1_title": false, "toc_cell": false, "toc_position": {}, "toc_section_display": "block", "toc_window_display": false } }, "nbformat": 4, "nbformat_minor": 2 }