{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "
LAMMPS Python Tutorials
" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "# Example 3: Working with Per-Atom Data" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "Author: [Richard Berger](mailto:richard.berger@outlook.com)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "2D circle of particles inside of box with LJ walls" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Setup system" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "from lammps import lammps" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "L = lammps()\n", "cmd = L.cmd" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "# 2d circle of particles inside a box with LJ walls\n", "import math\n", "\n", "b = 0\n", "x = 50\n", "y = 20\n", "d = 20\n", "\n", "# careful not to slam into wall too hard\n", "\n", "v = 0.3\n", "w = 0.08\n", " \n", "cmd.units(\"lj\")\n", "cmd.dimension(2)\n", "cmd.atom_style(\"bond\")\n", "cmd.boundary(\"f f p\")\n", "\n", "cmd.lattice(\"hex\", 0.85)\n", "cmd.region(\"box\", \"block\", 0, x, 0, y, -0.5, 0.5)\n", "cmd.create_box(1, \"box\", \"bond/types\", 1, \"extra/bond/per/atom\", 6)\n", "cmd.region(\"circle\", \"sphere\", d/2.0+1.0, d/2.0/math.sqrt(3.0)+1, 0.0, d/2.0)\n", "cmd.create_atoms(1, \"region\", \"circle\")\n", "cmd.mass(1, 1.0)\n", "\n", "cmd.velocity(\"all create 0.5 87287 loop geom\")\n", "cmd.velocity(\"all set\", v, w, 0, \"sum yes\")\n", "\n", "cmd.pair_style(\"lj/cut\", 2.5)\n", "cmd.pair_coeff(1, 1, 10.0, 1.0, 2.5)\n", "\n", "cmd.bond_style(\"harmonic\")\n", "cmd.bond_coeff(1, 10.0, 1.2)\n", "\n", "cmd.create_bonds(\"many\", \"all\", \"all\", 1, 1.0, 1.5)\n", "\n", "cmd.neighbor(0.3, \"bin\")\n", "cmd.neigh_modify(\"delay\", 0, \"every\", 1, \"check yes\")\n", "\n", "cmd.fix(1, \"all\", \"nve\")\n", "\n", "cmd.fix(2, \"all wall/lj93 xlo 0.0 1 1 2.5 xhi\", x, \"1 1 2.5\")\n", "cmd.fix(3, \"all wall/lj93 ylo 0.0 1 1 2.5 yhi\", y, \"1 1 2.5\")" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Visualize initial state" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "L.ipython.image(zoom=1.8)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Run simulation and visualize new state" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "cmd.thermo_style(\"custom step temp epair press\")\n", "cmd.thermo(100)\n", "output = cmd.run(40000)\n", "L.ipython.image(zoom=1.8)" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Accessing Atom data" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "L.numpy.extract_atom(\"x\")" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "L.numpy.extract_atom(\"id\")" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "L.numpy.extract_atom(\"v\")" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "L.numpy.extract_atom(\"f\")" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [ "L.numpy.extract_atom(\"type\")" ] }, { "cell_type": "code", "execution_count": null, "metadata": {}, "outputs": [], "source": [] } ], "metadata": { "kernelspec": { "display_name": "Python 3 (ipykernel)", "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": "3.12.7" } }, "nbformat": 4, "nbformat_minor": 4 }