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 "worksheets": [
  {
   "cells": [
    {
     "cell_type": "heading",
     "level": 1,
     "metadata": {},
     "source": [
      "1: Bonding in Solids"
     ]
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example number 1.1, Page number 1.4"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#importing modules\n",
      "import math\n",
      "from __future__ import division\n",
      "\n",
      "#Variable declaration\n",
      "IE_1 = 502     #first ionisation energy(kJ/mol)\n",
      "EA_B = -335    #electron affinity for B atom(kJ/mol)\n",
      "e = 1.602*10**-19\n",
      "r = 0.3      #inter ionic seperation(nm)\n",
      "epsilon0 = 8.85*10**-12      #permittivity of free space(C/N-m)\n",
      "\n",
      "#Calculation\n",
      "r = r*10**-9      #inter ionic seperation(m)\n",
      "N = 6.022*10**23*10**-3\n",
      "E = (-e**2*N)/(4*math.pi*epsilon0*r)      #electrostatic attraction energy(kJ/mol)\n",
      "dE = IE_1+EA_B+E;     #net change in energy per mole\n",
      "\n",
      "#Result\n",
      "print \"electrostatic attraction energy is\",int(E),\"kJ/mol\"\n",
      "print \"net change in energy is\",int(dE),\"kJ/mol\"\n",
      "print \"A+B- molecule will be stable\"\n",
      "print \"answer for net change,dE given in the book is wrong\""
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "electrostatic attraction energy is -463 kJ/mol\n",
        "net change in energy is -296 kJ/mol\n",
        "A+B- molecule will be stable\n",
        "answer for net change,dE given in the book is wrong\n"
       ]
      }
     ],
     "prompt_number": 2
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example number 1.2, Page number 1.5"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#importing modules\n",
      "import math\n",
      "from __future__ import division\n",
      "\n",
      "#Variable declaration\n",
      "IP_K = 4.1     #IP of K(eV)\n",
      "EA_Cl = 3.6     #EA of Cl(eV)\n",
      "e = 1.602*10**-19\n",
      "epsilon0 = 8.85*10**-12 \n",
      "\n",
      "#Calculation\n",
      "delta_E = IP_K - EA_Cl      #energy required(eV)\n",
      "#if their total energy is 0, delta_E = Ec\n",
      "Ec = delta_E\n",
      "R = e/(4*math.pi*epsilon0*Ec)      #seperation between ion pair(m)\n",
      "R = R*10**9          #seperation between ion pair(nm)\n",
      "R = math.ceil(R*10**3)/10**3;   #rounding off to 3 decimals\n",
      "\n",
      "#Result\n",
      "print \"energy required to form K+Cl- ion pair is\",delta_E,\"eV\"\n",
      "print \"seperation between ion pair is\",R,\"nm\""
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "energy required to form K+Cl- ion pair is 0.5 eV\n",
        "seperation between ion pair is 2.881 nm\n"
       ]
      }
     ],
     "prompt_number": 3
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example number 1.3, Page number 1.6"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#importing modules\n",
      "import math\n",
      "from __future__ import division\n",
      "\n",
      "#Variable declaration\n",
      "e = 1.602*10**-19\n",
      "EA = 3.65     #electron affinity of Cl(eV)\n",
      "IP = 5.14     #ionisation energy of Na(eV)\n",
      "epsilon0 = 8.85*10**-12\n",
      "r0 = 236      #equilibrium distance(pm)\n",
      "\n",
      "#Calculation\n",
      "r0 = r0*10**-12      #equilibrium distance(m)\n",
      "V = (-e**2)/(4*math.pi*epsilon0*r0)       ##potential energy(J)\n",
      "V = V/e       #potential energy(eV)\n",
      "Ue = V\n",
      "BE = -Ue - IP + EA       #bond energy(eV)\n",
      "BE = math.ceil(BE*10**3)/10**3;   #rounding off to 3 decimals\n",
      "\n",
      "#Result\n",
      "print \"bond energy for NaCl molecule is\",BE,\"eV\""
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "bond energy for NaCl molecule is 4.614 eV\n"
       ]
      }
     ],
     "prompt_number": 4
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "Example number 1.4, Page number 1.19"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "#importing modules\n",
      "import math\n",
      "from __future__ import division\n",
      "\n",
      "#Variable declaration\n",
      "e = 1.602*(10**-19)\n",
      "epsilon0 = 8.85*(10**-12)\n",
      "r0 = 0.281     #equilibrium seperation(nm)\n",
      "A = 1.748     #Madelung constant\n",
      "n = 9    #born repulsive exponent\n",
      "\n",
      "#Calculation\n",
      "r0 = r0*10**-9     #equilibrium seperation(m)\n",
      "CE = (A*e**2)*(1-(1/n))/(4*math.pi*epsilon0*r0)    #cohesive energy(J)\n",
      "CE = CE/e       #cohesive energy(eV)\n",
      "CE = math.ceil(CE*10**3)/10**3;   #rounding off to 3 decimals\n",
      "\n",
      "#Result\n",
      "print \"cohesive energy of NaCl is\",CE,\"eV\""
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "cohesive energy of NaCl is 7.966 eV\n"
       ]
      }
     ],
     "prompt_number": 5
    }
   ],
   "metadata": {}
  }
 ]
}