Helium Atom, Approximate Methods

Total Page:16

File Type:pdf, Size:1020Kb

Helium Atom, Approximate Methods Helium Atom, Approximate Methods 22nd April 2008 I. The Helium Atom and Variational Principle: Approximation Methods for Complex Atomic Systems The hydrogen atom wavefunctions and energies, we have seen, are deter- mined as a combination of the various quantum "dynamical" analogues of classical motions (translation, vibration, rotation) and a central-force inter- action (i.e, the Coulomb interaction between an electron and a nucleus). Now, we consider the Helium atom and will see that due to the attendant 3-body problem for which we cannot determine a close-for, first-principles analytic solution, we will have to find recourse in approximate methods. The Helium atom has 2 electrons with coordinates r1 and r2 as well as a single nucleus with coordinate R. The nuclues carries a Z = +2e charge. The Schrodinger equation is: 2 2 2 h¯ 2 h¯ 2 h¯ 2 1 2 (R; r1; r2) + −2M r − 2me r − 2me r ! 2e2 2e2 e2 + (R; r ; r ) = E (R; r ; r ) −4π R r − 4π R r 4π r r 1 2 1 2 o j − 1j o j − 2j o j 1 − 2j! where the symbol "nabla", when squared, is given by: @2 @2 @2 2 = + + r @x2 @y2 @z2 Keep in mind that the R, r, and r represent the Cartesian coordinates of each paticle. This is a 3-body problem and such problems are not solved exactly. Thus, the problem will be reformulated in terms of 2 variables. The first approximations: Mme , fix the nucleous at the origin (R) = 0. Thus, the Schrodinger equation in relative variables is: 1 2 2 2 h¯ 2 2 2e 1 1 e 1 2 (r1; r2) + + (r1; r2) = E (r1; r2) 2me −∇ − r −4πo r1 r2 4πo r2 r1 j − j Recall that the 2, representing the kinetic energy operator, in spherical r polar coordinates is: 1 @ @ 1 @ @ 1 @2 r2 + sinθ + 2 @r 1 @r 2 @θ 1 @θ 2 2 2 r1 1 1 r1sinθ1 1 1 r1sin θ1 @φ1 The Independent Electron Approximation to Solving the Helium Atom Schrodinger Equation If we neglect electron-electron repulsion in the Helium atom problem, we can simplify and solve the effective 2-body problem. Solve the relative motion problem (separate out the center of mass • motion as we have seen earlier) Center of mass is assumed to be the nucleus; good approximation for • heavier nuclei The Hamiltonian is now: ^ H = KEe1 + KEe2 + Vne1 + Vne2 2 2 h¯ 2 2 2e 1 1 = 1 2 + 2me −∇ − r − 4πo r1 r2 h¯2 2e2 1 h¯2 2e2 1 = − 2 + − 2 2m 1 4π r 2m 2 4π r e r − o 1 ! e r − o 2 ! Under the independent electron approximation, if we take the total He atom wavefunction as a product of the individual electron wavefunctions (here ap- proxmiated as hydrogen-like wavefunctions): Ψ(r1; r2) = (r1) (r2) H^ Ψ(r1; r2) = H^1 (r1) + H^2 (r2) 2 This yields E = E1 + E2. Recal the hydrogen-like energies and wavefunc- tions are: Ψ (r) = R (Zr=a )Y (θ; φ) (Z=1 for hydrogen, Z=2 for helium) • nlm nl o lm 2 Z Eh 1 Energies are: E = 2 • n − 2 n Thus, approximate wavefunctions and energies for helium: Ψn1; l1; m1; n2; l2; m2(r1; r2) spin = Ψn1; l1; m1(r1)Ψn2; l2; m2(r2) spin Z2E 1 1 E = h + n1;l1;m1;n2;l2;m2 2 2 2 − n1 n2 How sound is the independent electron approximation (no electron-electron repulsion model)? We can compare the predicted ionization potentials with the exerimental values. The ionization potential is the energy required to extract an electron from an atom. For the Helium atom, this can be represented as an equation such as: He He+ + e− ! The energy change associated is: ∆E = E E 2 He;1s − He;(1s) = 54:4eV ( 108:8eV ) = 54:4eV − − − The ground state energy for Helium can also be contrasted as: 2 0 2 Eh 1 1 E = E1s;1s = 2 + 2 − 2 1 1 = 4E − h = 108:8eV significantlytoonegative − 3 The experimental value for the ionization potential (from mass spectroscopic measurements) is 24.6 eV; so the independent electron approach entails sig- nifican error. Because the electrons are not allowed Coulombic repulsion, the energy required to remove a particular electron is higher than the ex- perimental value. This is also validated by the much lower (and thus more attractive/favorable) ground state energy predicted by the independent elec- tron model compared to experiment. Moving Beyond the Independent Electron Model: Perturba- tive and Variational Methods noindent Perturbation Theory The Helium atom Hamiltonian, we recall, is: 2 2 2 ^ h¯ 2 2 2e 1 1 e H = 1 2 (r1; r2) + + 2me −∇ − r − 4πo r1 r2 4πo r2 r1 j − j = H^ 0 + H^ 1 H^ 0 0 = E0 0 We see that the electron-electron repulsion term can be treated as a "per- turbation" to the independent electron Hamiltonian. in this sense, we can choose to define, develop, and include various orders of perturbative cor- rections to the energies and wavefunctions. WThough we are currently applying this to the problem of electron-electron repulsion, we will see later that modern advanced methods for electronic strucuture calculations em- ploy perturbation methods to account for important electron correlation. For now, we concern ourselves with the development of perturbation theory and application to correct for two-body Coulomb repulsion in the Helium atom. First Order Perturbation Theory First, expand the total wavefunction up to first order contributions: 0 1 n = n + n 0 1 En = En + En ^ 0 ^ 1 0 1 0 1 0 1 H + H n + n = En + En n + n Expanding the expression: ^ 0 0 ^ 1 0 ^ 0 1 ^ 1 1 0 0 1 0 0 1 1 1 H n + H n + H n + H n = En n + En n + En n + En n 4 The first terms on each side are equivalent. Last terms are approxi- mated/assumed to be neglibly small{this is a perturbation energy and wavefunction. This leaves: Expanding the expression: ^ 1 0 ^ 0 1 1 0 0 1 H n + H n = En + En n 1 1 0∗ Solve for n and En. Left multiply by n and integrate: Expanding the expression: 0∗ ^ 1 0 0∗ ^ 0 1 0∗ 1 0 0∗ 0 1 dτ n H n + dτ n H n = dτ n En n + dτ n En n Z Z Z Z ∗ ^ 0 0∗ ^ 0 1 ^ 0 0 1 Since H is Hermitian, dτ n H n = dτ H n n. R R 0∗ ^ 1 0 1 0 0∗ 0 0∗ 1 1 dτ n H n + dτ nEn n = En dτ n n + En Z Z Z 1 Solving for En , the fist order perturbative correction to the inde- pendent electron energy level for helium gives: 1 0∗ ^ 1 0 En = dτ n H n Z 0 1 Expilcitly, this means, En = En +En; we have added a "small" perturbative correction to the reference independent electron energy for a given energy level, n! Now, what about the correction to the wavefunction? Let's recall: ^ 1 0 ^ 0 1 1 0 0 1 H n + H n = En + En n 1 We will solve for n by expanding n as a linear combination of unper- turbed wavefunctions as follows: 5 0 0 n = n + anj j jX=6 n 0∗ Left multiply by k and integrate: 0∗ ^ 1 0 0∗ ^ 0 1 0∗ 1 0 0∗ 0 1 dτ k H n + dτ k H n = dτ k En n + dτ k En n Z Z Z Z 0∗ ^ 1 0 0∗ ^ 0 0 0∗ 1 0 0∗ 0 0 dτ k H n + dτ k H anj j = dτ k En n + dτ k En anj j Z Z jX=6 n Z Z jX=6 n 0∗ ^ 1 0 0 0∗ 0 1 0∗ 0 0 0∗ 0 dτ k H n + anjEj dτ k j = En dτ k n + En anj dτ k j Z jX=6 n Z Z jX=6 n Z a E0 E0 = E1 dτ 0∗ 0 dτ 0∗H^ 1 0 nk k − n n k n − k n Z Z Now, we consider two cases: k = n E1 = dτ 0∗H^ 1 0 ! n n n Z dτ 0∗H^ 1 0 H^ 1 k = n a = k n kn 6 ! nk E0 E0 ≡ E0 E0 R n − k n − k Thus, the first order correction to the wavefuntion is: 0 1 0 0 n = n + n = n + anj j jX=6 n ^ 1 0∗ ^ 1 0 0 Hjn 0 0 dτ k H n 0 = n + 0 0 j = n + 0 0 j En Ej ! R En Ek ! jX=6 n − jX=6 n − Higher Order Corrections For higher order corrections, energies and wavefunctions are expanded in 6 like manner: 0 1 2 0 1 2 n = n + n + n En = En + En + En The second-order correction to the energy is thus determined to be (see other sources for derivation): H^ 1 2 0∗ ^ 1 1 0∗ ^ 1 jn 0 En = dτ n H n = dτ n H 0 0 j En Ej Z Z jX=6 n − ^ 1 ^ 1 HnjHjn = 0 0 En Ej jX=6 n − Helium Atom: First Order Perturbation Correction to Account for Electron-Electron Repulsion From the above discussion, the first order correction to the ground state energy of Helium is: 1 0∗ ^ 1 0 En = dτ n H n Z If we assume an unperturbed wavefunction as the product of the 2 Helium electrons in 1s orbitals: 2 3 1=2 0 Z −Zr1 −Zr2 (r1; r2) = φ1s(r1)phi1s(r2) = e e 0 π ! 1 1 @ A H^ 1 = r12 Z6 1 E1 = dτ 0∗H^ 1 0 = dτe−Zr1 e−Zr2 e−Zr1 e−Zr2 n n n π2 r Z Z 12 Z6 e−2Zr1 e−2Zr2 5 = dτ = ZE π2 r 8 h Z 12 7 Thus, the ground state energy with first order correction is : 5 11 E = E0 + E1 = 4E + ZE = − E = 74:8eV 0 0 0 − h 8 h 4 h − Neglect of electron-electron repulsion: E = -108.8 eV • 0 First order correction: E = -78.8 eV • 0 13th order correction: E = -79.01 eV • 0 Experiment: E = -70.0 eV • Perturbation theory results may be greater or less than the true energy, • unlike variational results Perturbation, unlike variational theory, can be used to calculate any • energy level, not just the ground state.
Recommended publications
  • Solving the Schrödinger Equation for Helium Atom and Its Isoelectronic
    THE JOURNAL OF CHEMICAL PHYSICS 127, 224104 ͑2007͒ Solving the Schrödinger equation for helium atom and its isoelectronic ions with the free iterative complement interaction „ICI… method ͒ Hiroyuki Nakashima and Hiroshi Nakatsujia Quantum Chemistry Research Institute, Kyodai Katsura Venture Plaza 106, Goryo Oohara 1-36, Nishikyo-ku, Kyoto 615-8245, Japan and Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto 615-8510, Japan ͑Received 31 July 2007; accepted 2 October 2007; published online 11 December 2007͒ The Schrödinger equation was solved very accurately for helium atom and its isoelectronic ions ͑Z=1–10͒ with the free iterative complement interaction ͑ICI͒ method followed by the variational principle. We obtained highly accurate wave functions and energies of helium atom and its isoelectronic ions. For helium, the calculated energy was −2.903 724 377 034 119 598 311 159 245 194 404 446 696 905 37 a.u., correct over 40 digit accuracy, and for H−,itwas−0.527 751 016 544 377 196 590 814 566 747 511 383 045 02 a.u. These results prove numerically that with the free ICI method, we can calculate the solutions of the Schrödinger equation as accurately as one desires. We examined several types of scaling function g ␺ and initial function 0 of the free ICI method. The performance was good when logarithm functions were used in the initial function because the logarithm function is physically essential for three-particle collision area. The best performance was obtained when we introduce a new logarithm function containing not only r1 and r2 but also r12 in the same logarithm function.
    [Show full text]
  • Many-Electron System I – Helium Atom and Pauli Exclusion Principle
    Lecture 17 Many-electron System I { Helium Atom and Pauli Exclusion Principle Study Goal of This Lecture • Helium atom - many electron wavefunctions • Helium atom - variational ground state (screening) • Eigenstates of a two-spin system 17.1 Helium Atom Helium atom includes two electrons moving around a fixed nucleus with charge Z = 2, we can write down the Hamiltonian as: 2 2 2 2 ^ ~ 2 2 1 Ze Ze e H = − (r1 + r2) − ( + − ) 2me 4π0 r1 r2 r12 2 2 2 2 2 ~ 2 1 Ze ~ 2 1 Ze e = − r1 − − − r2 − + 2me 4π0 r1 2me 4π0 r2 4π0r12 (17.1) | {z } | {z } | {z } H^1 H^2 H^12 = H^1 + H^2 + H^12: 1 If H^12 = 0(or neglected) then the problem is exactly solved. Recall that for a total system composes of independent sub-systems H^T = H^1 + H^2 + ··· ; (17.2) and we can firstly solve all ^ n n n Hnφm = Emφm; (17.3) then the solution of H^T is the product states Y n = φ : (17.4) n If consider as many-electrons, i.e. H^n for the n-th electron. Then the product solu- tion is a natural "independent electron" solution. Even when the electron-electron interactions are non-zero, we will see the independent electorn approximation is a good starting point. Let's consider the Helium atom, we know: H^1φ1 = E1φ1; (17.5) H^2φ2 = E2φ2; and total E = E1 + E2. φ1; φ2 are Helium hydrogen-like atomic orbitals. We know the two ground states (neglect spin for a moment.) H^1φ1s(1) = E1sφ1s(1); (17.6) H^2φ1s(2) = E1sφ1s(2); number 1 and 2 denotes electorn 1 and electron 2 respectively.
    [Show full text]
  • Quantum Physics (UCSD Physics 130)
    Quantum Physics (UCSD Physics 130) April 2, 2003 2 Contents 1 Course Summary 17 1.1 Problems with Classical Physics . .... 17 1.2 ThoughtExperimentsonDiffraction . ..... 17 1.3 Probability Amplitudes . 17 1.4 WavePacketsandUncertainty . ..... 18 1.5 Operators........................................ .. 19 1.6 ExpectationValues .................................. .. 19 1.7 Commutators ...................................... 20 1.8 TheSchr¨odingerEquation .. .. .. .. .. .. .. .. .. .. .. .. .... 20 1.9 Eigenfunctions, Eigenvalues and Vector Spaces . ......... 20 1.10 AParticleinaBox .................................... 22 1.11 Piecewise Constant Potentials in One Dimension . ...... 22 1.12 The Harmonic Oscillator in One Dimension . ... 24 1.13 Delta Function Potentials in One Dimension . .... 24 1.14 Harmonic Oscillator Solution with Operators . ...... 25 1.15 MoreFunwithOperators. .. .. .. .. .. .. .. .. .. .. .. .. .... 26 1.16 Two Particles in 3 Dimensions . .. 27 1.17 IdenticalParticles ................................. .... 28 1.18 Some 3D Problems Separable in Cartesian Coordinates . ........ 28 1.19 AngularMomentum.................................. .. 29 1.20 Solutions to the Radial Equation for Constant Potentials . .......... 30 1.21 Hydrogen........................................ .. 30 1.22 Solution of the 3D HO Problem in Spherical Coordinates . ....... 31 1.23 Matrix Representation of Operators and States . ........... 31 1.24 A Study of ℓ =1OperatorsandEigenfunctions . 32 1.25 Spin1/2andother2StateSystems . ...... 33 1.26 Quantum
    [Show full text]
  • HELIUM ATOM R R2 R1 R2 R1
    HELIUM ATOM Now that we have treated the Hydrogen like atoms in some detail, we now proceed to discuss the next­simplest system: the Helium atom. In this situation, we have tow electrons – with coordinates z r1 and r2 – orbiting a nucleus with charge Z = 2 located at the point R. Now, for the hydrogen atom we were able to ignore the motion of the nucleus r2 by transforming to the center of mass. We then obtained a Schrödinger equation for a single R y effective particle – with a reduced mass that was very close to the electron mass – orbiting the x origin. It turns out to be fairly difficult to r1 transform to the center of mass when dealing with three particles, as is the case for Helium. However, because the nucleus is much more massive than either of the two electrons (MNuc ≈ 7000 mel) it is a very good z approximation to assume that the nucleus sits at the center of mass of the atom. In this approximate set of COM coordinates, then, R=0 r2 and the electron coordinates r and r measure 1 2 y the between each electron and the nucleus. Further, we feel justified in separating the motion of the nucleus (which will roughly x r correspond to rigidly translating the COM of the 1 atom) from the relative d the electrons orbiting the nucleus within the COM frame. Thus, in what follows, we focus only on the motion of the electrons and ignore the motion of the nucleus. We will treat the quantum mechanics of multiple particles (1,2,3…) in much the same way as we described multiple dimensions.
    [Show full text]
  • Comparing Many-Body Approaches Against the Helium Atom Exact Solution
    SciPost Phys. 6, 040 (2019) Comparing many-body approaches against the helium atom exact solution Jing Li1,2, N. D. Drummond3, Peter Schuck1,4,5 and Valerio Olevano1,2,6? 1 Université Grenoble Alpes, 38000 Grenoble, France 2 CNRS, Institut Néel, 38042 Grenoble, France 3 Department of Physics, Lancaster University, Lancaster LA1 4YB, United Kingdom 4 CNRS, LPMMC, 38042 Grenoble, France 5 CNRS, Institut de Physique Nucléaire, IN2P3, Université Paris-Sud, 91406 Orsay, France 6 European Theoretical Spectroscopy Facility (ETSF) ? [email protected] Abstract Over time, many different theories and approaches have been developed to tackle the many-body problem in quantum chemistry, condensed-matter physics, and nuclear physics. Here we use the helium atom, a real system rather than a model, and we use the exact solution of its Schrödinger equation as a benchmark for comparison between methods. We present new results beyond the random-phase approximation (RPA) from a renormalized RPA (r-RPA) in the framework of the self-consistent RPA (SCRPA) originally developed in nuclear physics, and compare them with various other approaches like configuration interaction (CI), quantum Monte Carlo (QMC), time-dependent density- functional theory (TDDFT), and the Bethe-Salpeter equation on top of the GW approx- imation. Most of the calculations are consistently done on the same footing, e.g. using the same basis set, in an effort for a most faithful comparison between methods. Copyright J. Li et al. Received 15-01-2019 This work is licensed under the Creative Commons Accepted 21-03-2019 Check for Attribution 4.0 International License.
    [Show full text]
  • HELIUM ATOM R R2 R1 R2 R1
    5.61 Physical Chemistry 25 Helium Atom page 1 HELIUM ATOM Now that we have treated the Hydrogen like atoms in some detail, we now proceed to discuss the next­simplest system: the Helium atom. In this situation, we have tow electrons – with coordinates z r1 and r2 – orbiting a nucleus with charge Z = 2 located at the point R. Now, for the hydrogen atom we were able to ignore the motion of the nucleus r2 by transforming to the center of mass. We then obtained a Schrödinger equation for a single R y effective particle – with a reduced mass that was very close to the electron mass – orbiting the x origin. It turns out to be fairly difficult to r1 transform to the center of mass when dealing with three particles, as is the case for Helium. However, because the nucleus is much more massive than either of the two electrons (MNuc ≈ 7000 mel) it is a very good z approximation to assume that the nucleus sits at the center of mass of the atom. In this approximate set of COM coordinates, then, R=0 r2 and the electron coordinates r and r measure 1 2 y the between each electron and the nucleus. Further, we feel justified in separating the motion of the nucleus (which will roughly x r correspond to rigidly translating the COM of the 1 atom) from the relative d the electrons orbiting the nucleus within the COM frame. Thus, in what follows, we focus only on the motion of the electrons and ignore the motion of the nucleus.
    [Show full text]
  • Lecture 2 Hamiltonian Operators for Molecules CHEM6085: Density
    CHEM6085: Density Functional Theory Lecture 2 Hamiltonian operators for molecules C.-K. Skylaris CHEM6085 Density Functional Theory 1 The (time-independent) Schrödinger equation is an eigenvalue equation operator for eigenfunction eigenvalue property A Energy operator wavefunction Energy (Hamiltonian) eigenvalue CHEM6085 Density Functional Theory 2 Constructing operators in Quantum Mechanics Quantum mechanical operators are the same as their corresponding classical mechanical quantities Classical Quantum quantity operator position Potential energy (e.g. energy of attraction of an electron by an atomic nucleus) With one exception! The momentum operator is completely different: CHEM6085 Density Functional Theory 3 Building Hamiltonians The Hamiltonian operator (=total energy operator) is a sum of two operators: the kinetic energy operator and the potential energy operator Kinetic energy requires taking into account the momentum operator The potential energy operator is straightforward The Hamiltonian becomes: CHEM6085 Density Functional Theory 4 Expectation values of operators • Experimental measurements of physical properties are average values • Quantum mechanics postulates that we can calculate the result of any such measurement by “averaging” the appropriate operator and the wavefunction as follows: The above example provides the expectation value (average value) of the position along the x-axis. CHEM6085 Density Functional Theory 5 Force between two charges: Coulomb’s Law r Energy of two charges CHEM6085 Density Functional Theory 6
    [Show full text]
  • Arxiv:1801.09977V3 [Physics.Atom-Ph] 1 Mar 2019 10 Helium
    Comparing many-body approaches against the helium atom exact solution Jing Li,1, 2 N. D. Drummond,3 Peter Schuck,1, 4, 5 and Valerio Olevano1, 2, 6, ∗ 1Universit´eGrenoble Alpes, 38000 Grenoble, France 2CNRS, Institut N´eel, 38042 Grenoble, France 3Department of Physics, Lancaster University, Lancaster LA1 4YB, United Kingdom 4CNRS, LPMMC, 38042 Grenoble, France 5CNRS, Institut de Physique Nucl´eaire, IN2P3, Universit´e Paris-Sud, 91406 Orsay, France 6European Theoretical Spectroscopy Facility (ETSF) (Dated: March 4, 2019) Over time, many different theories and approaches have been developed to tackle the many- body problem in quantum chemistry, condensed-matter physics, and nuclear physics. Here we use the helium atom, a real system rather than a model, and we use the exact solution of its Schr¨odinger equation as a benchmark for comparison between methods. We present new results beyond the random-phase approximation (RPA) from a renormalized RPA (r-RPA) in the framework of the self-consistent RPA (SCRPA) originally developed in nuclear physics, and compare them with various other approaches like configuration interaction (CI), quantum Monte Carlo (QMC), time- dependent density-functional theory (TDDFT), and the Bethe-Salpeter equation on top of the GW approximation. Most of the calculations are consistently done on the same footing, e.g. using the same basis set, in an effort for a most faithful comparison between methods. I. INTRODUCTION did not yet exist. It played a fundamental role in as- sessing the validity of quantum mechanics as a universal The neutral helium atom and other two-electron ion- theory that does not just apply to the hydrogen atom.
    [Show full text]
  • Quantum Field Theory and the Helium Atom: 101 Years Later
    QUANTUM FIELD THEORY AND THE HELIUM ATOM: 101 YEARS LATER ∗ J. SUCHER Department of Physics, University of Maryland College Park, MD 20742, U.S.A. October 6, 2018 Abstract Helium was first isolated on Earth in 1895, by Sir William Ramsey. One hundred and one years later, it seems like a good time to review our current theoretical understanding of the helium atom. Helium has played an important role both in the development of quantum mechanics and in quantum field theory. The early history of helium is sketched. Various aspects of the modern theory are described in some detail, including (1) the computation of fine structure to order α2Ry and α3Ry, (2) the decay of metastable states, and (3) Rydberg states and long-range forces. A brief survey is made of some of the recent arXiv:hep-ph/9612330v1 11 Dec 1996 work on the quantum field theory of He and He-like ions. ∗Invited talk: “Quantum Systems: New Trends and Methods”, Minsk, June 3-7, 1996 1 1 Introduction The title of my talk is inspired by that of a famous novel by Gabriel Garcia Marqu´ez: “100 years of solitude.” Helium, whose existence was not even suspected till the middle of the 19th century, has experienced exactly 101 years of attention since its terrestrial discovery in 1895. It has played a major role in the development of atomic, nuclear, and condensed matter physics. The helium atom, and its cousins, the He-like ions, continue to be a subject of active study. It has played an important role, second only to hydrogen, both in the development of quantum mechanics and that of quantum field theory (QFT).
    [Show full text]
  • 1 Exact Classical Quantum Mechanical Solution for Atomic
    Exact Classical Quantum Mechanical Solution for Atomic Helium Which Predicts Conjugate Parameters from a Unique Solution for the First Time Randell L. Mills, BlackLight Power, Inc., 493 Old Trenton Road, Cranbury, NJ 08512 (609)490-1090, [email protected], www.blacklightpower.com Abstract Quantum mechanics (QM) and quantum electrodynamics (QED) are often touted as the most successful theories ever. In this paper, this claim is critically evaluated by a test of internal consistency for the ability to calculate the conjugate observables of the nature of the free electron, ionization energy, elastic electron scattering, and the excited states of the helium atom using the same solution for each of the separate experimental measurements. It is found that in some cases quantum gives good numbers, but the solutions are meaningless numbers since each has no relationship to providing an accurate physical model. Rather, the goal is to mathematically reproduce an experimental or prior theoretical number using adjustable parameters including arbitrary wave functions in computer algorithms with precision that is often much greater (e.g. 8 significant figures greater) than possible based on the propagation of errors in the measured fundamental constants implicit in the physical problem. Given the constraints of adherence to physical laws and internal consistency, an extensive literature search indicates that quantum mechanics has never solved a single physical problem correctly including the hydrogen atom and the next member of the periodic chart, the helium atom. Rather than using postulated unverifiable theories that treat atomic particles as if they were not real, physical laws are now applied to the same problem.
    [Show full text]
  • Eindhoven University of Technology BACHELOR Coarse-Graining of Density Functional Theory Verhoeven, Lieke M
    Eindhoven University of Technology BACHELOR Coarse-graining of density functional theory Verhoeven, Lieke M. Award date: 2019 Link to publication Disclaimer This document contains a student thesis (bachelor's or master's), as authored by a student at Eindhoven University of Technology. Student theses are made available in the TU/e repository upon obtaining the required degree. The grade received is not published on the document as presented in the repository. The required complexity or quality of research of student theses may vary by program, and the required minimum study period may vary in duration. General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain Coarse-Graining of Density Functional Theory Bachelor End Project L.M. Verhoeven student number 0992218 July 4, 2019 Committee members: dr. B. Baumeier dr. ir. M.J.H. Anthonissen ir. W.L.J. Scharpach ................. Abstract In this thesis, the theoretical framework behind Density Functional Theory (DFT) and a new approach of DFT, called Coarse-Graining Density Function Theory (CGDFT), is discussed. CGDFT will be discussed in general and a practical numerical implementation is applied to single atoms. Standard DFT is a technique to obtain the minimum total energy (ground-state) of a system of interacting nuclei and electrons without solving the many-body Schr¨odingerequation of quantum mechanics directly.
    [Show full text]
  • Msc Physical Chemistry
    S.P.Mandali’s Ramnarain Ruia Autonomous College Program : M.Sc. Course: M.Sc. Physical Chemistry Course code: RPSCHEP Syllabus for Semester III & IV (Choice Based Credit System to be implemented from the Academic year 2019-20) Semester III Course Code Unit Topic Credits Lectures I Polymer Chemistry-I 15 II Modern Applications of Surface 15 Chemistry RPSCHEP301 4 III Photo Chemistry-I 15 IV Applications of Fluorescence 15 Phenomena I Advances in Nanomaterials 15 II Applied electrochemistry 15 RPSCHEP302 4 III Statistical Mechanics 15 IV Nuclear Chemistry 15 I Atomic structure 15 II 15 RPSCHEP303 Atomic spectroscopy 4 III Molecular Structure 15 IV Molecular spectroscopy 15 Electron Spectroscopy and I 15 Microscopy II Hyphenated Techniques 15 RPSCHEPEC-I 304 4 Thermal and Radioanalytical III 15 Methods IV Pulse Polarography 15 I Spectral Methods 15 II Electro-analytical Methods – I 15 RPSCHEPEC-II 304 4 III Radio-analytical Methods 15 IV Pulse polarography 15 RPSCHEP3P1 RPSCHEP3P2 Practicals 8 16 RPSCHEP3P3 RPSCHEP3P4 Semester IV Course Code Unit Topic Credits Lectures I Polymer Chemistry-II 15 II Polymer Chemistry-III 15 RPSCHEP401 III Bio-physical Chemistry and Green 4 15 Chemistry IV Photochemistry-II: Kinetics and 15 Applications I Solid State Chemistry 15 II Instrumental Methods 15 RPSCHEP402 4 III Lasers and super conductors 15 IV Non-equilibrium thermodynamics 15 I Symmetry in Chemistry 15 II N.M.R.Spectroscopy-I 15 RPSCHEP403 4 III ESR and Mossbauer Spectroscopy 15 IV 13C-N.M.R.Spectroscopy 15 Introduction to Intellectual I 15 Property
    [Show full text]