Constituent Atomic Orbitals Research Articles

DNA as a perfect quantum computer based on the quantum physics principles

DNA is a complex multi-resolution molecule whose theoretical study is a challenge. Its intrinsic multiscale nature requires chemistry and quantum physics to understand the structure and quantum informatics to explain its operation as a perfect quantum computer. Here, we present theoretical results of DNA that allow a better description of its structure and the operation process in the transmission, coding, and decoding of genetic information. Aromaticity is explained by the oscillatory resonant quantum state of correlated electron and hole pairs due to the quantized molecular vibrational energy acting as an attractive force. The correlated pairs form a supercurrent in the nitrogenous bases in a single band π\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\pi$$\\end{document}-molecular orbital (π\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\pi$$\\end{document}-MO). The MO wave function (Φ)\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$(\\Phi )$$\\end{document} is assumed to be the linear combination of the n constituent atomic orbitals. The central Hydrogen bond between Adenine (A) and Thymine (T) or Guanine (G) and Cytosine (C) functions like an ideal Josephson Junction. The approach of a Josephson Effect between two superconductors is correctly described, as well as the condensation of the nitrogenous bases to obtain the two entangled quantum states that form the qubit. Combining the quantum state of the composite system with the classical information, RNA polymerase teleports one of the four Bell states. DNA is a perfect quantum computer.

Reconstructing Molecular Orbitals with Laser-Induced Electron Tunneling Spectroscopy

Photoelectron spectroscopy in intense laser fields has proven to be a powerful tool for providing detailed insights into molecular structure. The ionizing molecular orbital, however, has not been reconstructed from the photoelectron spectra, because its phase information is difficult to access. Here, we propose a method to retrieve the phase information of the ionizing molecular orbital. By analyzing the interference pattern in the photoelectron spectrum, the weighted coefficients and the relative phases of the constituent atomic orbitals for a molecular orbital can be extracted. With this information, we reconstruct the highest occupied molecular orbital of N 2 . Our work provides a reliable and straightforward approach for reconstructing molecular orbitals with the photoelectron spectroscopy.

A comparative study of interference effects in (e, 2e) electron momentum profiles of CO2, ethylene and 1,3-butadiene

We report a comparative (e, 2e) study of intereference effects in the spherically-averaged electron momentum density distributions of the outermost orbitals of CO2, ethylene and 1,3-butadiene. The experiments on the three molecular orbitals, being each composed of 2p atomic orbitals, were performed in the symmetric noncoplanar geometry and at an incident electron energy of 1.2 keV. Interference patterns have then been obtained for each molecular orbital by dividing the experimental data by (e, 2e) cross section of a 2p atomic orbital calculated by using distorted wave impulse approximation. It is clearly demonstrated that interference patterns tell about constructive or destructive nature of the overlap between the constituent 2p atomic orbitals. Furthermore, it is shown that higher instrumental momentum resolution would be required for detailed studies on interference effects in cases when two of the constituent atomic orbitals with larger spatial separation are both oriented perpendicular to the molecular axis or plane.

Interference Effects on (e,2e) Electron Momentum Profiles ofCF4

Interference effects on electron momentum profiles have been studied using binary (e, 2e) spectroscopy for the three outermost molecular orbitals of CF(4), which are composed of the F 2p nonbonding atomic orbitals. An analysis of the measured spherically averaged electron momentum densities has clearly shown the presence of oscillatory structures having direct information about the internuclear distance between the F atoms. Furthermore, it is demonstrated that the phase of the oscillatory structures depends upon the orientation in space of the constituent atomic orbitals.

Phase-Sensitive Observation of a Spin-Orbital Mott State in Sr 2 IrO 4

Measurement of the quantum-mechanical phase in quantum matter provides the most direct manifestation of the underlying abstract physics. We used resonant x-ray scattering to probe the relative phases of constituent atomic orbitals in an electronic wave function, which uncovers the unconventional Mott insulating state induced by relativistic spin-orbit coupling in the layered 5d transition metal oxide Sr2IrO4. A selection rule based on intra-atomic interference effects establishes a complex spin-orbital state represented by an effective total angular momentum = 1/2 quantum number, the phase of which can lead to a quantum topological state of matter.

Orbital resolution of molecular information channels and stockholder atoms

Within the orbital description of the electronic structure of molecules the variational principles of the entropy deficiency and the entropy/information descriptors of the system communication channel are used to establish the orbital-representability (orthonormality) requirements in terms of the relevant conditional probabilities from the superposition principle of quantum mechanics. The orbital resolution of the Hirshfeld (stockholder) partition of the molecular electron density into the unbiased densities of bonded atoms is derived from the global and local principles of the maximum information-similarity between atoms-in-molecules and the free-atoms of the promolecule formulated in terms of the conditional probabilities of the (localized) atomic orbitals of constituent atoms. It is demonstrated that the universal (orbital- and atom-independent) local enhancement factors, which determine the unbiased orbital densities in such a division scheme, are the same as those characterizing the original (atom-condensed) partition of Hirshfeld. The orbital densities corresponding to these polarized atomic orbitals reproduce the overall densities of stockholder atoms and generate the effective orbital occupation numbers of bonded atoms in the molecular valence state.

Electronic structure of black phosphorus studied by polarized soft-x-ray emission and absorption spectroscopy

Soft-x-ray emission ($K\ensuremath{\beta}$ emission) and absorption ($K$ absorption) spectra of a black P single crystal polarized along each crystalline axis are presented for the first time. The experimental results indicate (1) the upper part of the valence band near the Fermi level is largely contributed by the $3{p}_{z}$ states, (2) the $3{p}_{y}$ orbital forms the middle to lower part of the $3p$-derived (or the first) valence band, (3) the $3{p}_{x}$ states spread over a whole range in the band, and (4) the conduction band has a clear but less drastic dependence on the nature of the constituent atomic orbitals. The emission and absorption curves were numerically calculated with the results of the band calculation of black P based on the self-consistent pseudopotential method and were compared with the experimental results. Excellent agreement has been found in the features of each spectrum, although a relative displacement of the emission and absorption spectra was observed between the experiment and the calculation. This discrepancy may be attributed to the overestimation of the $3p$-band width in the band calculation, although a many-body effect in the emission or absorption process cannot be entirely excluded.

Nuclear hyperfine interaction in ferrihemoglobin hydroxide: Theory

Expressions appropriate for the evaluation of the hyperfine splitting in ferric-hemoglobin hydroxide have been derived in the Hartree-Fock approximation using giant multielectron molecular-orbital wave functions formed as linear combinations of atomic orbitals of the constituent atoms and the molecular orbitals of the O${\mathrm{H}}^{\ensuremath{-}}$ complex incorporating overlap effects. Core orbitals as well as valence orbitals have been considered. The relevant multicenter matrix elements have been evaluated accurately by means of the analytical expressions which we have derived by employing a general closed-form expression developed previously for the coefficients of the expansion of a Slater orbital from one center onto the other. Various calculated electric field gradient components have been analyzed separately in terms of the valence and the core orbitals of the central ion (iron) interacting with the orbitals of the other constituent atoms and the complex O${\mathrm{H}}^{\ensuremath{-}}$. One finds that the local and distant parts of the field gradient due to O${\mathrm{H}}^{\ensuremath{-}}$ nearly cancel one another and, consequently, produce negligible effect on the hyperfine splitting of iron. The nitrogens of the porphyrin plane contribute dominantly to the splitting. Other surrounding atoms contribute less and their influence decreases rapidly as their distance from the central ion increases. On combining various contributions, the calculated hyperfine splitting comes out to be 1.44\ifmmode\pm\else\textpm\fi{}0.16 mm/sec, which agrees excellently with the experimental splitting 1.57 mm/sec observed by Lang and Marshall. The results from the present calculations have been compared with those obtained by Weissbluth and Maling employing semiempirical treatment on a porphyrin-hydroxide model compound. Their estimate is found to give negative sign to the splitting in contrast with our result. Sources of disagreement have been pointed out. Comparison has also been made with the previous calculations on hemin and the observed differences in the splittings in relation to the present system have been clarified. Arguments have been presented, which lead to the prediction of positive hyperfine splitting in ferric-hemoglobin compounds.

Orbital Radii and the Dependence of Bond Length Upon Ionicity, Hybridization, and Bond Order

Expressions for the dependence of hybrid orbital radii upon the constituent atomic orbitals and the ionicity of the bond to be formed are given. Using accurate bond-length data (±0.005 A) and a suitable expression for bond ionicity, atomic orbital radii have been obtained for the elements of the first four periods (other than transition metals). These radii can be used to calculate bond lengths in lone molecules, ionic crystals or metals or, alternatively, the experimental internuclear distance can be used in the same manner as the nuclear quadrupole coupling constant to describe the bond parameters in some detail.