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{
"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": {}
}
]
}
|
