{
 "metadata": {
  "name": ""
 },
 "nbformat": 3,
 "nbformat_minor": 0,
 "worksheets": [
  {
   "cells": [
    {
     "cell_type": "heading",
     "level": 1,
     "metadata": {},
     "source": [
      "Chapter 4 : Crystallography"
     ]
    },
    {
     "cell_type": "heading",
     "level": 3,
     "metadata": {},
     "source": [
      "Example 4.3 page no : 82"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "\n",
      "# Variables\n",
      "r_na = 0.98;\t\t\t#ionic radius of sodium in angstorm\n",
      "r_cl = 1.81;\t\t\t#ionic radius of chlorine in angstorm\n",
      "n = 4.;     \t\t\t#in fcc there are 4 Na and 4 Cl ions\n",
      "\n",
      "# Calculations\n",
      "a = ((2*r_na)+(2*r_cl));\t\t\t#latice constant\n",
      "apf = ((n*(4./3)*3.14*r_na**3)+(n*(4./3)*3.14*r_cl**3))/a**3;\n",
      "\n",
      "# Results\n",
      "print \"Lattice consmath.tant  =  \",a\n",
      "print \"atomic packing fraction of NaCl having FCC structure  =  %.2f\"%apf\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Lattice consmath.tant  =   5.58\n",
        "atomic packing fraction of NaCl having FCC structure  =  0.66\n"
       ]
      }
     ],
     "prompt_number": 1
    },
    {
     "cell_type": "heading",
     "level": 3,
     "metadata": {},
     "source": [
      "Example 4.4 pageno : 83"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "\n",
      "import math \n",
      "\n",
      "# Variables\n",
      "r = 1.278;\t\t\t#radius of copper in angstorm\n",
      "\n",
      "#copper has FCC structure\n",
      "a = round(4*r/math.sqrt(2),2);\t\t\t#in angstorm\n",
      "a1 = a*10**-8;\t\t\t        #in cm\n",
      "aw = 63.54;         \t\t\t#atomic weight of copper\n",
      "ne = 4.;\t\t\t            #fcc\n",
      "na = 6.023*10**23;\t\t\t    #Avagadro's no.\n",
      "p = aw*ne/(na*a1**3);\t\t\t#in g/cm**3\n",
      "\n",
      "# Results\n",
      "print \"a (in Angstorm)  =  %.2f A\"%a\n",
      "print \"Density of Copper (in gm/cm**3) : %.2f\"%p\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "a (in Angstorm)  =  3.61 A\n",
        "Density of Copper (in gm/cm**3) : 8.97\n"
       ]
      }
     ],
     "prompt_number": 7
    },
    {
     "cell_type": "heading",
     "level": 3,
     "metadata": {},
     "source": [
      "Example 4.5 pageno : 84"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "\n",
      "# Variables\n",
      "w_na = 23.;    \t\t\t#atomic weight of Na\n",
      "w_cl = 35.5;\t\t\t#atomic weight of Cl\n",
      "w = w_na+w_cl;\t\t\t#effective no.of atoms in FCC structure\n",
      "n = 4.;     \t\t\t#FCC\n",
      "\n",
      "# Calculations\n",
      "na = 6.023*10**23;\t\t\t#Avagadrro's no.\n",
      "w_4 = w*n/na;\t\t\t#weight of 4 molecules in gm\n",
      "p = 2.18;\t\t\t#density in gm/cm**3\n",
      "a3 = (w*n)/(na*p)\n",
      "a = a3**(1./3)\n",
      "#a = (w_4/p)**(1/3);\t\t\t#in cm\n",
      "a1 = a*10**8;\t\t\t#in angstorm\n",
      "d = a1/2;\n",
      "\n",
      "# Results\n",
      "print \"unit cell dimension (in angstorm)  =  %.2f A\"%a1\n",
      "print \"Distance between two adjacent atoms (in Angstorm)  =  %.2f A\"%d\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "unit cell dimension (in angstorm)  =  5.63 A\n",
        "Distance between two adjacent atoms (in Angstorm)  =  2.81 A\n"
       ]
      }
     ],
     "prompt_number": 13
    },
    {
     "cell_type": "heading",
     "level": 3,
     "metadata": {},
     "source": [
      "Example 4.6 pageno : 84"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "\n",
      "# Variables\n",
      "n = 2.;          \t\t\t#BCC    \n",
      "p = 7.86;\t    \t\t    #density in gm/cm**3\n",
      "aw = 55.85;\t\t        \t#atomic weight of iron\n",
      "\n",
      "# Calculations\n",
      "na = 6.023*10**23;\t\t            \t#Avagadrro's no.\n",
      "a = ((aw*n)/(na*p))**(1./3);\t\t\t#in cm\n",
      "a1 = a*10**8;\t                \t\t#in angstorm\n",
      "r = math.sqrt(3)*a1/4;\n",
      "\n",
      "# Results\n",
      "print \"unit cell dimension of iron (in angstorm)  =  %.2f A\"%a1\n",
      "print \"atomic radius  =  %.3f A\"%r\n"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "unit cell dimension of iron (in angstorm)  =  2.87 A\n",
        "atomic radius  =  1.242 A\n"
       ]
      }
     ],
     "prompt_number": 15
    }
   ],
   "metadata": {}
  }
 ]
}