Add Activity 4 and 5

msspecbook/Activity04/Activity04.ipynb

@@ -0,0 +1,53 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "id": "d053c16f-22ca-44ce-a58d-03e73c1a5554",
+   "metadata": {
+    "editable": true,
+    "slideshow": {
+     "slide_type": ""
+    },
+    "tags": []
+   },
+   "source": [
+    "# From single scattering to multiple scattering"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "2f4bc57a-1dbf-4b24-8660-f5866e2303ea",
+   "metadata": {
+    "editable": true,
+    "slideshow": {
+     "slide_type": ""
+    },
+    "tags": []
+   },
+   "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": "3.11.13"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 5
+}

msspecbook/Activity05/Activity05.ipynb

@@ -0,0 +1,127 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "id": "ff0fc2d9-b53e-4d29-883b-6d6303d76eb2",
+   "metadata": {
+    "editable": true,
+    "slideshow": {
+     "slide_type": ""
+    },
+    "tags": []
+   },
+   "source": [
+    "# Forward scattering regime"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "7f10b898-4fc8-40fd-a477-05e736a5a255",
+   "metadata": {
+    "editable": true,
+    "slideshow": {
+     "slide_type": ""
+    },
+    "tags": []
+   },
+   "source": [
+    "In photoelectron diffraction, it is well known that for high kinetic energy of the photoelectron (typically > 900 eV), the scattering factor has a strong peak in the forward direction. It means that photoelectrons are almost not deviated after a scattering event.\n",
+    "\n",
+    "Peaks of intentisity are then usually observed for dense atomic directions of the sample. This is the forward scattering approximation.\n",
+    "\n",
+    "For such high kinetic energy, the matrix inversion algorithm cannot be used since the memory needed for storing the matrix itself would be generally too high. The matrix will contain\n",
+    "{math}```(N \\times (L_{max}+1)^2)^2``` elements of complex type with double precision (64 bits)"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "id": "524878ef-3b96-47f5-9e9c-dc54f860b1a4",
+   "metadata": {
+    "editable": true,
+    "slideshow": {
+     "slide_type": ""
+    },
+    "tags": []
+   },
+   "source": [
+    "How much memory would you need for this matrix for a hemispherical cluster of copper 15 angstroms thick (1 MFP) where the number of basis functions Lmax = 25 ?"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 11,
+   "id": "e6f5b739-bcbf-4a2f-9c51-5e409079392a",
+   "metadata": {
+    "editable": true,
+    "slideshow": {
+     "slide_type": ""
+    },
+    "tags": []
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "606 atoms, 2.685 TB\n"
+     ]
+    }
+   ],
+   "source": [
+    "import numpy as np\n",
+    "\n",
+    "# lattice constant of fcc copper\n",
+    "a = 3.6\n",
+    "# radius of the cluster\n",
+    "r = 15\n",
+    "# volume of the cluster\n",
+    "V = .5 * (4/3) * np.pi * r**3\n",
+    "# volume of the cell\n",
+    "v = a**3\n",
+    "# number of atoms in the unit cell\n",
+    "n = 4\n",
+    "# number of atoms in the cluster\n",
+    "N = int(V/v * n)\n",
+    "\n",
+    "Lmax = 25\n",
+    "M = (N * (Lmax+1)**2 )**2 * 2 * 64 / 8\n",
+    "print(f\"{N:d} atoms, {M/1e12:.3f} TB\")"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "id": "c3161733-d4d7-498b-90a8-6fdaf2c4c306",
+   "metadata": {
+    "editable": true,
+    "slideshow": {
+     "slide_type": ""
+    },
+    "tags": []
+   },
+   "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": "3.11.13"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 5
+}

msspecbook/_toc.yml

@@ -5,5 +5,6 @@ format: jb-book
 root: intro
 chapters:
 - file: Activity01/Activity01
-- file: Activity02/Activity02
+
-- file: Activity03/Activity03
+#- file: Activity02/Activity02
+#- file: Activity03/Activity03