{ "metadata": { "name": "" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 15: Quantum Mechanics" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 15.1, Page 15.24" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import *\n", "\n", "# Given \n", "E = 1000 # energy of electron in eV\n", "delta_x = 1e-10 # error in position in m\n", "e = 1.6e-19 # charge on an electron in C\n", "m = 9.1e-31 # mass of electron in kg\n", "h = 6.62e-34 # Planck constant in J-sec\n", "\n", "#Calculations\n", "p = sqrt(2 * m * E * e)\n", "delta_p = h / (4 * pi * delta_x)\n", "P = (delta_p / p) * 100\n", "\n", "#Result\n", "print \"Percentage of uncertainty in momentum is %.1f%%\"%P" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Percentage of uncertainty in momentum is 3.1%\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 15.3, Page 15.25" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import *\n", "\n", "# Given \n", "E = 500 # energy of electron in eV\n", "delta_x = 2e-10 # error in position in m\n", "e = 1.6e-19 # charge on an electron in C\n", "m = 9.1e-31 # mass of electron in kg\n", "h = 6.62e-34 # Planck constant in J-sec\n", "\n", "#Calculations\n", "p = sqrt(2 * m * E * e)\n", "delta_p = h / (4 * pi * delta_x)\n", "P = (delta_p / p) * 100\n", "\n", "#Result\n", "print \"Percentage of uncertainty in momentum is %.2f%%\"%P" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Percentage of uncertainty in momentum is 2.18%\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 15.4, Page 15.25" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import *\n", "\n", "# Given \n", "delta_lambda = 1e-6 # accuracy in wavelength of its one part\n", "lamda = 1e-10 # wavelength of x-ray in m\n", "h = 6.62e-34 # Planck constant in J-sec\n", "\n", "#Calculations\n", "delta_x = lamda / (4 * pi * delta_lambda)\n", "\n", "#Result\n", "print \"Uncertainty in position is %.2f micrometer\"%(delta_x*10**6)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Uncertainty in position is 7.96 micrometer\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 15.5, Page 15.26" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import *\n", "\n", "# Given \n", "delta_x = 1e-10 # error in position in m\n", "e = 1.6e-19 # charge on an electron in C\n", "m = 9.1e-31 # mass of electron in kg\n", "h = 6.62e-34 # Planck constant in J-sec\n", "\n", "#Calculations\n", "delta_p = h / (4 * pi * delta_x)\n", "\n", "#Result\n", "print \"Uncertainty in momentum is %.2e kg m/sec\"%delta_p" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Uncertainty in momentum is 5.27e-25 kg m/sec\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 15.6, Page 15.26" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import *\n", "\n", "# Given \n", "M = 5.4e-26 # momentum of electron in kg-m/sec\n", "p = 0.05 # percentage accuracy in momentum\n", "e = 1.6e-19 # charge on an electron in C\n", "m = 9.1e-31 # mass of electron in kg\n", "h = 6.62e-34 # Planck constant in J-sec\n", "\n", "#Calculations\n", "delta_m = p * M / 100\n", "delta_x = h / (4 * pi * delta_m)\n", "\n", "#Result\n", "print \"Uncertainty in position is %.3f micrometer\"%(delta_x * 10**6)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Uncertainty in position is 1.951 micrometer\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 15.7, Page 15.27" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import *\n", "\n", "# Given \n", "r = 0.53e-10 # radius of hydrogen atom in m\n", "e = 1.6e-19 # charge on an electron in C\n", "m = 9.1e-31 # mass of electron in kg\n", "h = 6.62e-34 # Planck constant in J-sec\n", "\n", "#Calculations\n", "delta_M = h / (4 * pi * r)\n", "delta_k = delta_M**2 / (2 * m)\n", "\n", "#Result\n", "print \"Minimum energy of electron is %.3e J\"%delta_k" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Minimum energy of electron is 5.428e-19 J\n" ] } ], "prompt_number": 6 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 15.8, Page 15.27" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import *\n", "\n", "# Given \n", "v = 5e3 # speed of electron in m/sec\n", "a = 0.003 # percentage accuracy in measurement of speed \n", "e = 1.6e-19 # charge on an electron in C\n", "m = 9.1e-31 # mass of electron in kg\n", "h = 6.62e-34 # Planck constant in J-sec\n", "\n", "#Calculations\n", "delta_v = v * a / 100\n", "delta_p = m * delta_v\n", "delta_x = h / (4 * pi * delta_p)\n", "\n", "#Result\n", "print \"Uncertainty in determining the position of electron is %.3e m\"%delta_x" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Uncertainty in determining the position of electron is 3.859e-04 m\n" ] } ], "prompt_number": 7 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 15.9, Page 15.27" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import *\n", "\n", "# Given \n", "v = 6.6e4 # speed of electron in m/sec\n", "a = 0.01 # percentage accuracy in measurement of speed \n", "e = 1.6e-19 # charge on an electron in C\n", "m = 9.1e-31 # mass of electron in kg\n", "h = 6.6e-34 # Planck constant in J-sec\n", "\n", "#Calculations\n", "delta_v = v * a / 100\n", "delta_p = m * delta_v\n", "delta_x = h / (4 * pi * delta_p)\n", "\n", "#Result\n", "print \"Uncertainty in determining the position is %.2e m\"%delta_x" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Uncertainty in determining the position is 8.74e-06 m\n" ] } ], "prompt_number": 8 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 15.10, Page 15.28" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import *\n", "\n", "# Given \n", "v = 3e7 # speed of electron in m/sec \n", "e = 1.6e-19 # charge on an electron in C\n", "m = 9.1e-31 # mass of electron in kg\n", "h = 6.62e-34 # Planck constant in J-sec\n", "c = 3e8 # speed of light in m/sec\n", "\n", "#Calculations\n", "delta_p = m * v / sqrt(1 - (v/c)**2)\n", "delta_x = h / (4 * pi * delta_p)\n", "\n", "#Result\n", "print \"Uncertainty in determining the position is %.2e m\"%delta_x" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Uncertainty in determining the position is 1.92e-12 m\n" ] } ], "prompt_number": 9 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 15.11, Page 15.28" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import pi\n", "\n", "# Given \n", "t = 2.5e-14 # life time of hydrogen atom in exited state in sec\n", "h = 6.62e-34 # Planck constant in J-sec\n", "\n", "#Calculations\n", "delta_E = h / (4 * pi * t)\n", "\n", "#Result\n", "print \"Minimum error in measurement of the energy is %.2e J\"%delta_E" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Minimum error in measurement of the energy is 2.11e-21 J\n" ] } ], "prompt_number": 10 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 15.12, Page 15.28" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import *\n", "\n", "# Given \n", "t = 10**-8 # life time of atom in exited state in sec\n", "h = 6.62e-34 # Planck constant in J-sec\n", "\n", "#Calculations\n", "delta_f = 1 / (4 * pi * t)\n", "\n", "#Result\n", "print \"Minimum uncertainty in frequency is %.2e sec\"%delta_f" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Minimum uncertainty in frequency is 7.96e+06 sec\n" ] } ], "prompt_number": 12 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 15.13, Page 15.29" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import pi\n", "\n", "# Given \n", "delta_x = 20e-10 # uncertainty in position in m\n", "e = 1.6e-19 # charge on an electron in C\n", "m = 9.1e-31 # mass of electron in kg\n", "m_ = 1.67e-27 # mass of proton in kg\n", "c = 3e8 # speed of light in m/sec\n", "h = 6.62e-34 # Planck constant in J-sec\n", "\n", "#Calculations\n", "delta_v1 = h / (4 * pi * m * delta_x)\n", "delta_v2 = h / (4 * pi * m_ * delta_x)\n", "r = delta_v2 / delta_v1\n", "\n", "#Result\n", "print \"Ratio of uncertainty in velocity of a proton and an electron is %.2e\"%r" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Ratio of uncertainty in velocity of a proton and an electron is 5.45e-04\n" ] } ], "prompt_number": 13 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 15.14, Page 15.29" ] }, { "cell_type": "code", "collapsed": false, "input": [ " \n", "# Given \n", "delta_x = 1e-10 # width of box in m\n", "e = 1.6e-19 # charge on an electron in C\n", "m = 9.1e-31 # mass of electron in kg\n", "c = 3e8 # speed of light in m/sec\n", "h = 6.62e-34 # Planck constant in J-sec\n", "n = 1 # for n=1\n", "\n", "#Calculations\n", "E = (n**2 * h**2) / (8 * m * delta_x**2)\n", "n = 2 # for n=2\n", "E_ = (n**2 * h**2) / (8 * m * delta_x**2)\n", "\n", "#Result\n", "print \"Energy of electron - \\nFor (n=1) energy is %.2e J\\nFor (n=2) energy is %.2e J\"%(E,E_)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Energy of electron - \n", "For (n=1) energy is 6.02e-18 J\n", "For (n=2) energy is 2.41e-17 J\n" ] } ], "prompt_number": 14 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 15.15, Page 15.30" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# Given \n", "l = 1e-10 # width of box in m\n", "e = 1.6e-19 # charge on an electron in C\n", "m = 9.1e-31 # mass of electron in kg\n", "c = 3e8 # speed of light in m/sec\n", "h = 6.62e-34 # Planck constant in J-sec\n", "n = 1 # for n=1\n", "\n", "#Calculations\n", "E = (n**2 * h**2) / (8 * m * l**2)\n", "n = 2 # for n=2\n", "E_ = (n**2 * h**2) / (8 * m * l**2)\n", "d = E_ - E\n", "\n", "#Result\n", "print \"Energy difference is %.2e J\"%d" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Energy difference is 1.81e-17 J\n" ] } ], "prompt_number": 15 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 15.16, Page 15.30" ] }, { "cell_type": "code", "collapsed": false, "input": [ " \n", "# Given \n", "l = 3e-10 # width of box in m\n", "e = 1.6e-19 # charge on an electron in C\n", "m = 9.1e-31 # mass of electron in kg\n", "c = 3e8 # speed of light in m/sec\n", "h = 6.62e-34 # Planck constant in J-sec\n", "n = 1 # For n=1\n", "\n", "#Calculations\n", "E = (n**2 * h**2) / (8 * m * l**2)\n", "n = 2 # For n=2\n", "E_ = (n**2 * h**2) / (8 * m * l**2)\n", "n = 3 # For n=3\n", "E__ = (n**2 * h**2) / (8 * m * l**2)\n", "\n", "#Result\n", "print \"Energy of electron -\\nFor (n=1) is %.1e J\\nFor (n=2) is %.2e J\\nFor (n=3) is %.2e J\"%(E,E_,E__)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Energy of electron -\n", "For (n=1) is 6.7e-19 J\n", "For (n=2) is 2.68e-18 J\n", "For (n=3) is 6.02e-18 J\n" ] } ], "prompt_number": 16 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 15.17, Page 15.30" ] }, { "cell_type": "code", "collapsed": false, "input": [ " \n", "# Given \n", "l = 2.5e-10 # width of box in m\n", "e = 1.6e-19 # charge on an electron in C\n", "m = 9.1e-31 # mass of electron in kg\n", "c = 3e8 # speed of light in m/sec\n", "h = 6.62e-34 # Planck constant in J-sec\n", "\n", "#Calculations\n", "n = 1 # for n=1\n", "E = (n**2 * h**2) / (8 * m * l**2)\n", "n = 2 # for n=2\n", "E_ = (n**2 * h**2) / (8 * m * l**2)\n", "\n", "#Result\n", "print \"Energy of electron -\\nFor (n=1) is %.2e J\\nFor (n=2) is %.3e J\"%(E,E_)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Energy of electron -\n", "For (n=1) is 9.63e-19 J\n", "For (n=2) is 3.853e-18 J\n" ] } ], "prompt_number": 17 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 15.18, Page 15.31" ] }, { "cell_type": "code", "collapsed": false, "input": [ " \n", "# Given \n", "l = 1e-14 # width of box in m\n", "e = 1.6e-19 # charge on an electron in C\n", "m = 1.67e-27 # mass of neutron in kg\n", "c = 3e8 # speed of light in m/sec\n", "h = 6.62e-34 # Planck constant in J-sec\n", "\n", "#Calculations\n", "n = 1 # for n=1\n", "E = (h**2) / (8 * m * l**2)\n", "\n", "#Result\n", "print \"Lowest energy of neutron confined in the nucleus is %.2e J\"%E" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Lowest energy of neutron confined in the nucleus is 3.28e-13 J\n" ] } ], "prompt_number": 20 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 15.19, Page 15.31" ] }, { "cell_type": "code", "collapsed": false, "input": [ " \n", "# Given \n", "l = 1e-10 # width of box in m\n", "e = 1.6e-19 # charge on an electron in C\n", "m = 9.1e-31 # mass of electron in kg\n", "c = 3e8 # speed of light in m/sec\n", "h = 6.63e-34 # Planck constant in J-sec\n", "\n", "#Calculations\n", "n = 1 # for n=1\n", "p1 = (n * h) / (2 * l)\n", "E = (n**2 * h**2) / (8 * m * l**2)\n", "n = 2 # for n=2\n", "p2 = (n * h) / (2 * l)\n", "E_ = (n**2 * h**2) / (8 * m * l**2)\n", "\n", "#Result\n", "print \"Energy of electron -\\nFor (n=1) is %.2e J\\nFor (n=2) is %.2e J\"%(E,E_)\n", "print \"\\nMomentum of electron -\\nFor (n=1) is %.3e kg-m/sec\\nFor (n=2) is %.2e kg-m/sec\"%(p1,p2)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Energy of electron -\n", "For (n=1) is 6.04e-18 J\n", "For (n=2) is 2.42e-17 J\n", "\n", "Momentum of electron -\n", "For (n=1) is 3.315e-24 kg-m/sec\n", "For (n=2) is 6.63e-24 kg-m/sec\n" ] } ], "prompt_number": 21 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 15.20, Page 15.32" ] }, { "cell_type": "code", "collapsed": false, "input": [ " \n", "# Given \n", "l = 1e-10 # length of box in m\n", "m = 9.1e-31 # mass of electron in kg\n", "c = 3e8 # speed of light in m/sec\n", "h = 6.62e-34 # Planck constant in J-sec\n", "\n", "#Calculations\n", "n = 1 # for n=1\n", "E1 = (n**2 * h**2) / (8 * m * l**2)\n", "lambda1 =2*l\n", "n = 2 # for n=2\n", "E2 = (n**2 * h**2) / (8 * m * l**2)\n", "lambda2 =2*l/2\n", "n = 3 # for n=3\n", "E3 = (n**2 * h**2) / (8 * m * l**2)\n", "lambda3 =2*l/3\n", "\n", "#Results\n", "print \"Energy Eigen value of electron -\\nFor (n=1) is %.2e J\\nFor (n=2) is %.2e J\\nFor (n=3) is %.2e J\"%(E1,E2,E3)\n", "print \"\\nde-Broglie wavelength of electron -\\nFor (n=1) is %.f A\\nFor (n=2) is %.f A \\nFor (n=3) is %.3f A\"%(lambda1*1e10,lambda2*1e10,lambda3*1e10)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Energy Eigen value of electron -\n", "For (n=1) is 6.02e-18 J\n", "For (n=2) is 2.41e-17 J\n", "For (n=3) is 5.42e-17 J\n", "\n", "de-Broglie wavelength of electron -\n", "For (n=1) is 2 A\n", "For (n=2) is 1 A \n", "For (n=3) is 0.667 A\n" ] } ], "prompt_number": 22 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 15.21, Page 15.32" ] }, { "cell_type": "code", "collapsed": false, "input": [ " \n", "# Given \n", "E1 = 3.2e-18 # minimum energy possible for a particle entrapped in a one dimensional box in J\n", "e = 1.6e-19 # charge on an electron in C\n", "m = 9.1e-31 # mass of electron in kg\n", "c = 3e8 # speed of light in m/sec\n", "h = 6.62e-34 # Planck constant in J-sec\n", "\n", "#Calculations\n", "E1 = E1 / e # in eV\n", "n = 2 # for n=2\n", "E2 = n**2 * E1\n", "n = 3 # for n=3\n", "E3 = n**2 * E1\n", "n = 4 # for n=4\n", "E4 = n**2 * E1\n", "\n", "#Result\n", "print \"Energy Eigen values -\\nFor (n=2) for %.f eV\\nFor (n=3) is %.f eV\\nFor (n=4) is %.f eV\"%(E2,E3,E4)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Energy Eigen values -\n", "For (n=2) for 80 eV\n", "For (n=3) is 180 eV\n", "For (n=4) is 320 eV\n" ] } ], "prompt_number": 23 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 15.22, Page 15.33" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import *\n", "\n", "# Given \n", "l = 4e-10 # width of box in m\n", "E = 9.664e-17 # energy of electron in J\n", "e = 1.6e-19 # charge on an electron in C\n", "m = 9.1e-31 # mass of electron in kg\n", "c = 3e8 # speed of light in m/sec\n", "h = 6.62e-34 # Planck constant in J-sec\n", "\n", "#Calculations\n", "n = 1 # for n=1\n", "E1 = (n**2 * h**2) / (8 * m * l**2)\n", "N = sqrt(E / E1)\n", "p = ((N) * h) / (2 * l)\n", "\n", "#Result\n", "print \"Order of exited state is %d\\nMomentum of electron is %.2e kg-m/sec\"%(N,p)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Order of exited state is 16\n", "Momentum of electron is 1.33e-23 kg-m/sec\n" ] } ], "prompt_number": 24 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 15.23, Page 15.33" ] }, { "cell_type": "code", "collapsed": false, "input": [ " \n", "# Given \n", "l = 10e-10 # width of box containing electron in m\n", "E = 9.664e-17 # energy of electron in J\n", "M = 0.001 # mass of glass marble in kg\n", "l_ = 0.2 # width of box containing marble in m\n", "e = 1.6e-19 # charge on an electron in C\n", "m = 9.1e-31 # mass of electron in kg\n", "c = 3e8 # speed of light in m/sec\n", "h = 6.62e-34 # Planck constant in J-sec\n", "\n", "#Calculations\n", "# For electron\n", "n = 1 # for n=1\n", "E1 = (n**2 * h**2) / (8 * m * l**2)\n", "E2 = 2**2* E1\n", "E3 = 3**2 * E1\n", "# For glass marble\n", "E1_ = h**2/(8*M*l_**2)\n", "E2_ = 2**2 * E1_\n", "E3_ = 3**2 *E1_\n", "\n", "#Result\n", "print \"\\nEnergy levels of electron- \\nFor (n=1) is %.2e J\\nFor (n=2) is %.2e J\\n For (n=3) is %.2e J\"%(E1,E2,E3)\n", "print \"\\nEnergy levels of marble- \\nFor (n=1) is %.2e J\\nFor (n=2) is %.2e J\\nFor (n=3) is %.2e J\"%(E1_,E2_,E3_)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "\n", "Energy levels of electron- \n", "For (n=1) is 6.02e-20 J\n", "For (n=2) is 2.41e-19 J\n", " For (n=3) is 5.42e-19 J\n", "\n", "Energy levels of marble- \n", "For (n=1) is 1.37e-63 J\n", "For (n=2) is 5.48e-63 J\n", "For (n=3) is 1.23e-62 J\n" ] } ], "prompt_number": 25 } ], "metadata": {} } ] }