The two-dimensional (2D) hydrogen atom is a fundamental atomic model that is important for various technologies based on 2D materials. Here, the atomic model is revisited to enhance understanding of the hydrogen wavefunctions. Unlike in previous studies, we propose an alternative expression of azimuthal wavefunctions, which are the eigenstates of the square of angular momentum and exhibit rotational symmetry. Remarkably, our expression leads to the rotation and oscillation along the azimuthal direction of the probability densities, which do not appear in the conventional wavefunctions. These behaviors are validated by the numerical results obtained through the 2D finite difference approach. Variation in oscillator strengths due to the rotation of wavefunctions is observed in our proposed 2D hydrogen wavefunctions, whereas those due to the conventional wavefunctions remain constant. More importantly, the proposed wavefunctions’ advantage is illustrating the orbital shapes of the planar hydrogen states, whose orientation is labeled here using Cartesian representation for the first time. This study can be applied to visualize the orbital characteristics of the states in quantum confinement with a radial potential.
The two-dimensional (2D) hydrogen atom is a fundamental atomic model that is important for various technologies based on 2D materials. Here, the atomic model is revisited to enhance understanding of the hydrogen wavefunctions. Unlike in previous studies, we propose an alternative expression of azimuthal wavefunctions, which are the eigenstates of the square of angular momentum and exhibit rotational symmetry. Remarkably, our expression leads to the rotation and oscillation along the azimuthal direction of the probability densities, which do not appear in the conventional wavefunctions. These behaviors are validated by the numerical results obtained through the 2D finite difference approach. Variation in oscillator strengths due to the rotation of wavefunctions is observed in our proposed 2D hydrogen wavefunctions, whereas those due to the conventional wavefunctions remain constant. More importantly, the proposed wavefunctions’ advantage is illustrating the orbital shapes of the planar hydrogen states, whose orientation is labeled here using Cartesian representation for the first time. This study can be applied to visualize the orbital characteristics of the states in quantum confinement with a radial potential.
This chapter physical properties of the hydrogen atom and its Hamiltonian function as a particle in a spherically symmetric potential having a wave function as a product of the radial function and spherical harmonic function. Hereafter, it comes to two independent wave equations: the radial equation and the angular equation. After some derivation, it is shown that the angular equation is a product of the azimuthal angle equation and polar angle equation (as discussed in the previous chapter). The azimuthal angle equation is similar to the particle in a ring problem from the previous chapter and after some derivation the polar angle equation becomes an associated Legendre equation with well-known polynomials as solutions. Next, the solution to the radial equation is presented which becomes after some derivation an associated Laguerre equation with well-known polynomials as solutions and from this result is obtained the energy equation for the hydrogen-like atom. Subsequently, it is derived the normalization constant of the radial function. Afterwards, the numerical analysis of the radial equation of the hydrogen atom along with its corresponding Fortran code is presented. Finally, the hydrogen atomic orbitals equations and plots are depicted followed by the fine structure of the hydrogen (198 words).
The Bohr model of the hydrogen atom, despite its heuristic success in predicting discrete energy levels, is fundamentally incompatible with the probabilistic interpretation of modern quantum mechanics. In this work, we present a pedagogical derivation of Bohr’s results directly from the time-independent Schrödinger equation in three dimensions. By applying two successive geometric constraints, first, a genuine dimensional reduction to a 2D planar system (not a naive restriction of the spherical Laplacian), and second, a radial localization to a fixed radius, we demonstrate that the resulting radial-azimuthal equation yields the quantized Bohr orbits. We show that the energy levels En = −13.6/n2 eV and orbital radii r[n] = n² ao emerge naturally from the wavefunction normalization combined with the de Broglie standing-wave condition. Special attention is given to the correct form of the 2D Laplacian, which differs from the 3D Laplacian restricted to θ = π/2 by a term (1/r) ∂/∂r. This approach provides a clear conceptual bridge between the diffuse quantum cloud and the classical planetary picture.
In this chapter, we focus on three-dimensional problems that have rotational symmetry, with a concentrated effort on describing the properties of the hydrogen atom. This is an exactly solvable problem that is extremely important. To get there, we first have to describe how we work in spherical coordinate systems, and we need to develop the general rules for the factorization method. We develop the concept of a vector operator, of radial momentum, and the rules needed to solve problems by the Schrödinger factorization method. We first examine the isotropic harmonic oscillator, and then we establish the energy scales of hydrogen and solve first for the energies and eigenstates and then the wavefunctions in position and momentum space. We derive the Kramers–Pasternak relations for expectation values of powers of r and then focus on important experiments, which include the Pickering–Fowler lines, the discovery of deuterium, visualizing the atom in momentum space with e-2e spectroscopy, Rydberg atoms, the Lamb shift, and hyperfine structure and its applications to radio astronomy.
A research note connecting the shapes of atomic orbitals to four-dimensional geometry. The hydrogen atom possesses a hidden SO(4) symmetry (Pauli 1926) arising from conservation of the Runge-Lenz vector. In momentum space, hydrogen wavefunctions are exactly the spherical harmonics on the 3-sphere S³ (Fock 1935 stereographic projection). The familiar d and f orbital shapes are therefore 3D equatorial shadows of 4D hyperspherical harmonics. Covers: the Runge-Lenz vector and SO(4) Lie algebra; the Fock stereographic projection theorem; the Kustaanheimo-Stiefel transform (3D hydrogen ≡ 4D harmonic oscillator, exact); the SO(4,2) conformal group encoding the full hydrogen spectrum in a single representation; n-sphere generalization table; and open research directions including an interactive visualization paper (Am. J. Phys. target), angular-momentum dependence of AMEM matrix elements, and lanthanide crystal field analysis in the S³ harmonic basis.
The original intention of the author’s preoccupation with the quantum-mechanical behaviour of simple atoms and molecules such as Hydrogen and Helium was, on the one hand, the elegant simplicity of Niels Bohr’s atom model for Hydrogen, describing the metastable states of the excited electrons by planar concentric electron orbits, and, on the other hand, the hardly intelligible wave mechanical approach of Heisenberg, Schrödinger and others, describing mainly atoms with multiple electrons by three-dimensional orbitals which were characterized by probabilities of presence. Thereby the question arose whether it would be possible to find alternative atom models with well-defined electron trajectories. Therein, Louis de Broglie’s thesis of the wavy nature of electron motion implicating standing waves would have to be implemented. Nevertheless, as reviewed in the introduction, the orthodox three-dimensional concept influenced the own thinking in such a way that three-dimensional constellations for the electronic excited states were conceived. The break-through was achieved for the electronic ground state in the form of the spin-orbit coupling where the spin acts as a perpetuum mobile, inducing the orbital angular momentum h/2π. Furthermore, the insight was gained that a circularly rotating electron intrinsically corresponds to a harmonic oscillator, thus fulfilling the condition of a standing wave. Based on this concept, a double planar model was established for the H2-molecule which could be empirically verified by X-ray data from literature. However, for the two electrons containing Helium a 2D-array seemed impossible since the Pauli-principle seemed to be violated. After a long stepwise succession of 3D-attempts which turned out to be impossible—not least since eccentric forces are not possible in such a system—the here presented 2D-version for Helium was found, composed by two imaginary orthogonal electron orbits. It will enable in a subsequent publication the quantum mechanical interpretation of the thermal-radiative behaviour of Helium which was reported in the author’s publication nine years ago.
Abstract We present a real-time, interactive visualization platform for hydrogen atomic orbitals that achieves O(1) constant-time computational complexity for probability density evaluation. Using the Neural-Matrix Synaptic Resonance Network (NM-SRN v2.0 AGI QSC) architecture, we demonstrate visualization of complete hydrogen wavefunctions ψ_nlm(r,θ,φ) for quantum states with principal quantum numbers n ≤ 4, rendering 500,000 particles at interactive frame rates (30-60 FPS) on consumer hardware. The system provides instant orbital transitions, analytical energy calculations, real-time radial and angular probability distributions, and comprehensive quantum state analysis. Unlike traditional grid-based approaches requiring O(N³) operations, our definitive computing framework enables exploration of arbitrary quantum states with zero pre-computation and constant performance regardless of orbital complexity. We validate results against analytical solutions for radial wavefunctions and spherical harmonics, achieving exact agreement for all computed expectation values. This work establishes a new paradigm for quantum visualization in educational and research contexts, making quantum mechanical concepts intuitively accessible through real-time interactive exploration. Keywords: Hydrogen atom, quantum mechanics, orbital visualization, real-time rendering, probability density, spherical harmonics, definitive computing, educational technology