Examination of the molecular properties of D-fructose and L-sorbose by abinitio LCAO-MO calculations

1984 ◽  
Vol 62 (8) ◽  
pp. 1506-1511 ◽  
Author(s):  
Walter A. Szarek ◽  
Sirkka-Liisa Korppi-Tommola ◽  
Olivier R. Martin ◽  
Vedene H. Smith Jr.
Keyword(s):  
Point Charge ◽  
Population Analysis ◽  
Sweet Taste ◽  
Molecular Properties ◽  
Intramolecular Interactions ◽  
Mo Calculations ◽  
Hydrogen Atoms ◽  
Mulliken Population ◽  
Hydroxyl Hydrogen ◽  
Lcao Mo

Abinitio SCF LCAO-MO calculations at the STO-3G level have been performed on β-D-fructopyranose (1) and α-L-sorbopyranose (2) using crystallographic data as the geometrical input. Molecular properties of 1 and 2 are discussed in terms of orbital energies, total energy, ionization potentials, Mulliken population analysis, and electrostatic potentials, with a particular emphasis on the possible consequences of these features as regards the sweet taste of these two ketoses. No correlation was found, for example, with the electrostatic, point-charge distribution since the calculated hydrogen-bonding abilities would lead to the prediction of 2 being sweeter than 1. On the other hand, non-bonded overlap populations between oxygen and hydroxyl-hydrogen atoms reveal the presence of intramolecular interactions, which may have a determinant influence on the taste of these molecules and which could explain why D-fructose is much sweeter than its epimer at C-5, namely, L-sorbose.

Population Analysis with Hydrogen 2 p Polarization Functions Included in the INDO Basis Set

1980 ◽  
Vol 35 (12) ◽  
pp. 1350-1353
Author(s):  
J. C. Facelli ◽  
R. H. Contreras
Keyword(s):  
Ab Initio ◽  
Population Analysis ◽  
Basis Set ◽  
Ab Initio Methods ◽  
Mulliken Population Analysis ◽  
Indo Method ◽  
Hydrogen Atoms ◽  
Mulliken Population ◽  
Electron Population ◽  
Polarization Functions

Abstract Mulliken population analysis with 2p polarization functions included in the AO basis set of the INDO method has been performed for a set of molecules containing hydrogen as well as first row atoms. It is found that this enlargement of the basis set yields an increasing electron population in hydrogen atoms, in agreement with trends found in “ab initio” methods.

Quantum Mechanical Study of Clean and H-Covered α-MoO3(100) Surface

2003 ◽  
Vol 02 (02) ◽  
pp. 245-256 ◽  
Author(s):  
A. Sayede ◽  
B. Khelifa ◽  
C. Mathieu ◽  
H. Aourag
Keyword(s):  
Electronic Properties ◽  
Density Functional ◽  
Population Analysis ◽  
Chemical Properties ◽  
Hydrogen Atoms ◽  
Mulliken Population ◽  
Hartree Fock ◽  
Mechanical Study ◽  
Quantum Mechanical Study ◽  
Local Electronic Structure

Structure and electronic properties of the α-MoO3(100) surface, as well as H adsorption on the α-MoO3(100) surface have been studied with periodic slab Hartree–Fock calculations. Gradient corrected density functional calculations have been performed in this study. The structure and electronic properties of the (100) surface are in agreement with experimental and previous theoretical results. Local electronic structure near the different surface oxygen sites are analyzed with Mulliken Population Analysis. The oxide is partially ionic and the symmetrically oxygens exhibit more ionic feature while the terminal oxygens are more covalent. Electrostatic potentials show broad negative minima above the terminal oxygen centers, which suggest that electrophilic adparticles, like H, resulting from surface reactions, will be attracted preferentially at these sites. The results of the H adsorption on the (100) surface are interpreted based on charge-transfer interactions between the surface and H species. It is found that terminal oxygen sites are the most stable binding site. Ionic relaxation of the α-MoO3(100) surface for the adsorption of hydrogen has no effect on the chemical properties and hydrogen atoms adsorbed favorably on the α-MoO3(100) surface at full coverage.

scholarly journals Crystal structure of new formamidinium triiodide jointly refined by single-crystal XRD, Raman scattering spectroscopy and DFT assessment of hydrogen-bond network features

2021 ◽  
Vol 77 (7) ◽  
pp. 692-695
Author(s):  
Artem A. Ordinartsev ◽  
Andrey A. Petrov ◽  
Konstantin A. Lyssenko ◽  
Andrey V. Petrov ◽  
Eugene A. Goodilin ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Raman Scattering ◽  
Population Analysis ◽  
Hydrogen Atoms ◽  
Mulliken Population ◽  
Triclinic Space Group ◽  
Raman Scattering Spectroscopy ◽  
Scattering Spectra ◽  
Bond Network ◽  
Raman Scattering Spectra

A novel triiodide phase of the formamidinium cation, CH5N2 +·I3 −, crystallizes in the triclinic space group P\overline{1} at a temperature of 110 K. The structure consists of two independent isolated triiodide ions located on inversion centers. The centrosymmetric character of I3 − was additionally confirmed by the observed pronounced peaks of symmetrical oscillations of I3 − at 115–116 cm−1 in Raman scattering spectra. An additional structural feature is that each terminal iodine atom is connected with three neighboring planar formamidinium cations by N—H...I hydrogen bonding with the N—H...I bond length varying from 2.81 to 3.08 Å, forming a deformed two-dimensional framework of hydrogen bonds. A Mulliken population analysis showed that the calculated charges of hydrogen atoms correlate well with hydrogen-bond lengths. The crystal studied was refined as a three-component twin with domain ratios of 0.631 (1):0.211 (1):0.158 (1).

A Computational Study on Structural and Electronic Properties of 1-(4-Chlorophenyl)-2-{[5-(4-Chlorophenyl)-1,2,3-Oxadiazol-2-Yl]Sulfanyl}Ethanone

2019 ◽  
Vol 892 ◽  
pp. 1-7
Author(s):  
Pek Lan Toh ◽  
Montha Meepripruk ◽  
Rosfayanti Rasmidi
Keyword(s):  
Density Functional ◽  
Computational Study ◽  
Molecular System ◽  
Population Analysis ◽  
Atomic Charge ◽  
Dft Method ◽  
Basis Sets ◽  
Hydrogen Atoms ◽  
Mulliken Population ◽  
Total Energies

In this paper, a first principle Density Functional Theory (DFT) method was conducted to study the geometric and electronic structures of 1-(4-chlorophenyl)-2-{[5-(4-chlorophenyl) -1,3,4-oxadiazol-2-yl] sulfanyl} ethanone, C16H10Cl2N2O2S. Using B3LYP level of theory with four basis sets of 6-31G**, 6-31++G**, 6-311G**, and 6-311++G**, the equilibrium structure of the title molecule was used to determine the total energies, Frontier molecular orbital’s energies, Mulliken atomic charges, and others. The computed findings present that four total energies obtained are close to each other, with the corresponding values of-59716.06 eV, -59709.42 eV, -59708.56 eV, and-59716.51 eV, respectively for B3LYP/6-31G**, B3LYP/6-31++G**, B3LYP/6-311G**, and B3LYP/6-311++G** methods. The calculated HOMO-LUMO energy gaps were predicted in the range of 4.001 eV - 4.089 eV. In this study, the atomic charge values of molecular system were also determined using Mulliken Population Analysis (MPA) approach. For DFT/B3LYP/6-311G** level of calculation, the computed results show that the atom of C8 accommodates the highest negative charge in the title molecular system. All the oxygen, nitrogen, and chloride atoms are having negative charges, whereas all the hydrogen atoms are having positive charges. In addition, the dipole moment value was also determined to be 1.4758 Debye by employing DFT/B3LYP/6-311G** level of theory.

Relativistic quantum crystallography of diphenyl- and dicyanomercury. Theoretical structure factors and Hirshfeld atom refinement

2019 ◽  
Vol 75 (5) ◽  
pp. 705-717 ◽  
Author(s):  
Lukáš Bučinský ◽  
Dylan Jayatilaka ◽  
Simon Grabowsky
Keyword(s):  
Population Analysis ◽  
Relativistic Quantum ◽  
Perfect Match ◽  
Relativistic Effects ◽  
Basis Set ◽  
Hydrogen Atoms ◽  
Mulliken Population ◽  
Theoretical Structure ◽  
Structure Factors ◽  
The Impact

Quantum crystallographic refinement of heavy-element-containing compounds is a challenge, because many physical effects have to be accounted for adequately. Here, the impact and magnitude of relativistic effects are compared with those of electron correlation, polarization through the environment, choice of basis set and treatment of thermal motion effects on the structure factors of diphenylmercury(II) [Hg(Ph)2] and dicyanomercury(II) [Hg(CN)2]. Furthermore, the individual atomic contributions to the structure factors are explored in detail (using Mulliken population analysis and the exponential decay of atomic displacement parameters) to compare the contributions of lighter atoms, especially hydrogen atoms, against mercury. Subsequently, relativistic Hirshfeld atom refinement (HAR) is validated against theoretical structure factors of Hg(Ph)2 and Hg(CN)2, starting from perturbed geometries, to test if the relativistic variant of HAR leads to multiple solutions. Generally, relativistic HAR is successful, leading to a perfect match with the reference geometries, but some limitations are pointed out.

scholarly journals Ni Oxidation State and Ligand Saturation Impact on the Capability of Octaazamacrocyclic Complexes to Bind and Reduce CO2

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4139
Author(s):  
Barbora Vénosová ◽  
Ingrid Jelemenská ◽  
Jozef Kožíšek ◽  
Peter Rapta ◽  
Michal Zalibera ◽  
...  
Keyword(s):  
Quantum Theory ◽  
Oxidation State ◽  
Central Atom ◽  
Population Analysis ◽  
Mulliken Population Analysis ◽  
Mulliken Population ◽  
Theoretical Methods ◽  
Ni Oxidation ◽  
Shed Light

Two 15-membered octaazamacrocyclic nickel(II) complexes are investigated by theoretical methods to shed light on their affinity forwards binding and reducing CO2. In the first complex 1[NiIIL]0, the octaazamacrocyclic ligand is grossly unsaturated (π-conjugated), while in the second 1[NiIILH]2+ one, the macrocycle is saturated with hydrogens. One and two-electron reductions are described using Mulliken population analysis, quantum theory of atoms in molecules, localized orbitals, and domain averaged fermi holes, including the characterization of the Ni-CCO2 bond and the oxidation state of the central Ni atom. It was found that in the [NiLH] complex, the central atom is reduced to Ni0 and/or NiI and is thus able to bind CO2 via a single σ bond. In addition, the two-electron reduced 3[NiL]2− species also shows an affinity forwards CO2.

Role of population analysis in LCAO-MO theory of transition-metal clusters

1975 ◽  
Vol 25 (11) ◽  
pp. 1201-1207 ◽  
Author(s):  
J. Málek ◽  
R. A. Evarestov ◽  
A. N. Ermoshkin ◽  
B. Hejda ◽  
K. Polák
Keyword(s):  
Transition Metal ◽  
Metal Clusters ◽  
Population Analysis ◽  
Transition Metal Clusters ◽  
Lcao Mo Theory ◽  
Lcao Mo ◽  
Mo Theory

scholarly journals Effect of Doping on the Photoelectric Properties of Borophene

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Chunhong Zhang ◽  
Zhongzheng Zhang ◽  
Wanjun Yan ◽  
Xinmao Qin
Keyword(s):  
Optical Properties ◽  
Band Gap ◽  
Population Analysis ◽  
Covalent Bond ◽  
Infrared Light ◽  
Chemical Bonds ◽  
Mulliken Population Analysis ◽  
Mulliken Population ◽  
Photoelectric Properties ◽  
Effect Of Doping

Borophene is a new type of two-dimensional material with a series of unique and diversified properties. However, most of the research is still in its infancy and has not been studied in depth. Especially in the field of semiconductor optoelectronics, there is no related research on the modulation of photoelectric properties of borophene. In this work, we focus on the effect of doping on the photoelectric properties of borophene by using the first-principles pseudopotential plane wave method. We calculate the geometric structure, electronic structure, Mulliken population analysis, and optical properties of impurity (X = Al, Ga) doped α-sheet borophene. The results show that α-sheet borophene is an indirect band gap semiconductor with 1.396 eV. The band gap becomes wider after Al and Ga doping, and the band gap values are 1.437 eV and 1.422 eV, respectively. Due to the orbital hybridization between a small number of Al-3p electrons and Ga-4p state electrons and a large number of B 2p state electrons near the Fermi level, the band gap of borophene changes and the peak value of the electron density of states reduces after doping. Mulliken population analysis shows that the B0-B bond is mainly covalent bond, but there is also a small amount of ionic bond. However, when the impurity X is doped, the charge transfer between X and B atoms increases significantly, and the population of the corresponding X-B bonds decreases, indicating that the covalent bond strength of the chemical bonds in the doped system is weakened, and the chemical bonds have significant directionality. The calculation of optical properties shows that the static dielectric constant of the borophene material increases, and the appearance of a new dielectric peak indicates that the doping of Al and Ga can enhance the ability of borophene to store electromagnetic energy. After doping, the peak reflectivity decreases and the static refractive index n0 increases, which also fills the gap in the absorption of red light and infrared light by borophene materials. The research results provide a basis for the development of borophene materials in the field of infrared detection devices. The above results indicate that doping can modulate the photoelectric properties of α-sheet borophene.

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