Mg2Cl5 - and Mg3Cl7 - Superhalogen Anions

2008 ◽  
Vol 61 (9) ◽  
pp. 712 ◽  
Author(s):  
Iwona Anusiewicz
Keyword(s):  
Green Function ◽  
Crystal Lattice ◽  
Global Minimum ◽  
Binding Energies ◽  
Basis Sets ◽  
Energy Structure ◽  
Electron Detachment ◽  
Geometrical Structures ◽  
Outer Valence ◽  
Electron Binding Energies

The vertical electron detachment energies of Mg2Cl5– and Mg3Cl7– superhalogen anions were calculated at the outer valence Green function level with 6–311+G(3df) basis sets. These species were found to form rather unusual geometrical structures, each of which corresponds to a stable anionic state exhibiting superhalogen nature. The global minimum structure of Mg2Cl5– was found to possess D3h symmetry, which can be described as a system in which two central magnesium atoms are linked via a symmetrical triangle formed by three chlorine atoms, whereas the lowest-energy structure for Mg3Cl7– was found to have C3v symmetry, which can be viewed as a fragment of chloromagnesite crystal lattice. Extremely large electron binding energies of these anions (exceeding 6.5 eV in all cases) were predicted and discussed.

THE PERFORMANCE OF SELECTED AB INITIO METHODS IN ESTIMATING ELECTRON BINDING ENERGIES OF SUPERHALOGEN ANIONS

2011 ◽  
Vol 10 (01) ◽  
pp. 93-109 ◽  
Author(s):  
CELINA SIKORSKA ◽  
DOROTA IGNATOWSKA ◽  
SYLWIA FREZA ◽  
PIOTR SKURSKI
Keyword(s):  
Ab Initio ◽  
Binding Energies ◽  
Basis Sets ◽  
Electron Detachment ◽  
Hartree Fock ◽  
Moller Plesset ◽  
Very High ◽  
Outer Valence ◽  
Electron Binding Energies ◽  
Electron Binding

The capability of reproducing the vertical electron detachment energies (VDE) of four representative superhalogen anions was tested using the selected ab initio (Hartree-Fock (HF), second, third, and fourth-order Møller-Plesset perturbational scheme (MP2, MP3, MP4), coupled-cluster CCSD(T), and outer valence Green function (OVGF)) methods together with the variety of one-electron basis sets. Certain theoretical treatments (e.g. MP2/aug–cc–pVTZ and MP2/6-311+G(3df)) were found to be satisfactory for preliminary estimates of electron binding energies of superhalogen anions, whereas the use of the OVGF/6-311+G(3df) approach has been proven to assure a very high accuracy of the results.

scholarly journals Tripodal Podand Ligand with a Superhalogen Nature as an Effective Molecular Trap

Symmetry ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1441
Author(s):  
Adrianna Cyraniak ◽  
Marcin Czapla
Keyword(s):  
Metal Cations ◽  
Equilibrium Structure ◽  
Binding Energies ◽  
Electron Detachment ◽  
Tripodal Ligand ◽  
Ionic Complexes ◽  
System A ◽  
Moller Plesset ◽  
Fragmentation Processes ◽  
Outer Valence

Tris(2-methoxyethyl) fluoroborate anion (TMEFA), anovel tripodal ligand based on the BF4− superhalogen anion, is proposed and was investigated theoretically using ab initio MP2 (second-order Møller-Plesset perturbational method) and OVGF (outer valence Green function) methods. The studied molecule comprises three 2-methoxyethoxy groups (-O-CH2-CH2-O-CH3) connected to a central boron atom, which results in the C3-symmetry of the compound. The resulting anion was stable against fragmentation processes and its vertical electron detachment energy was found to be 5.72 eV. Due to its equilibrium structure resembling that of classical tripodal podands, the [F-B(O-CH2-CH2-O-CH3)3]− anion is capable of binding metal cations using its three arms, and thus may form strongly bound ionic complexes such as [F-B(O-CH2-CH2-O-CH3)3]−/Li+ and [F-B(O-CH2-CH2-O-CH3)3]−/Mg2+. The binding energies predicted for such compounds far exceed those of the similar neutral classical podand ligands, which likely makes the [F-B(O-CH2-CH2-O-CH3)3]− system a more effective molecular trap or steric shielding agent with respect to selected metal cations.

Toward understanding tautomeric switching in 4-hydroxynaphthaldehyde and its dimers: A DFT and quantum topology study

2015 ◽  
Vol 14 (03) ◽  
pp. 1550016 ◽  
Author(s):  
Aeshah El-Amri ◽  
Shaaban A. Elroby ◽  
Oliver Kühn ◽  
Rifaat H. Hilal
Keyword(s):  
Density Functional ◽  
Structural Parameters ◽  
Minimum Energy ◽  
Potential Energy Function ◽  
Binding Energies ◽  
Basis Sets ◽  
Energy Structure ◽  
Dispersion Interactions ◽  
Quantum Topology ◽  
Aldehyde Groups

The electronic structures and stabilities of all benzenoid (enol) and quinonoid (keto) forms of 4-hydroxynaphthaldehyde (ALD-14) have been investigated using density functional theory (DFT) with a range of functionals and basis sets. The anti-enol form represents the global minimum energy structure. Low rotation barriers of both the hydroxyl and the aldehyde groups characterize this form. Fourier analysis of the potential energy function for rotation indicate that the conformational preference of ALD-14 is determined by both the dipole–dipole repulsion and bond moments interactions. Further, three different ALD-14 dimer complexes are investigated, i.e. head-to-tail (HT), head-to-head (HH), and stacked (S) forms. The analysis of natural bond order, quantum topology features of the Laplacian of the electron density, binding energies and structural parameters of these dimers point to comparable stabilities of the HT and S-dimers, with a preference for a stacking contact. The origin of its stability can be traced to π-conjugative, H-bonding and dispersion interactions.

Geometrical and vibrational DFT studies of HOBr·(H2O)n clusters (n = 1–4)

2003 ◽  
Vol 81 (9) ◽  
pp. 961-970 ◽  
Author(s):  
Cristina Maria P Santos ◽  
Roberto B Faria ◽  
Wagner B De Almeida ◽  
Juan O Machuca-Herrera ◽  
Sérgio P Machado
Keyword(s):  
Binding Energy ◽  
Hydrogen Bonds ◽  
Water Molecule ◽  
Vibrational Spectra ◽  
Low Frequency ◽  
Binding Energies ◽  
Basis Sets ◽  
Dft Studies ◽  
Geometrical Structures ◽  
Stable Structures

The geometrical structures and the vibrational spectra of the HOBr·(H2O)n clusters (n = 1–4) have been calculated at the DFT level of theory, using the pBP method and the DN* and DN** numerical basis sets. The results showed that the interaction involving the H of the HOBr and the O of the water molecule represent the preferred arrangements for these hydrated compounds. Both HOBr·H2O and HOBr·(H2O)2 clusters presented stable structures with syn and anti conformations, the syn being the most stable. The HOBr·(H2O)3 and the HOBr·(H2O)4 clusters have presented stable cyclic structures. In the HOBr·H2O and HOBr·(H2O)2 clusters, low-frequency stretching values could be assigned to hydrogen bonds, but the same could not be done so clearly for the HOBr·(H2O)3 and the HOBr·(H2O)4 cyclic clusters. The binding energies were also determinated for these HOBr hydrated clusters, showing that the addition of a water molecule to the HOBr·H2O and HOBr·(H2O)2 clusters increases the binding energy by approximately 4 kcal mol–1, while the addition of a water molecule to the HOBr·(H2O)3 cluster decreases this value by 4 kcal mol–1.Key words: DFT, numerical basis, HOBr·(H2O)n, clusters.

Accurate density-functional calculation of core-electron binding energies with a scaled polarized triple-zeta basis set. VI: Extension to boron-containing molecules.

1999 ◽  
Vol 77 (1) ◽  
pp. 24-27 ◽  
Author(s):  
Germán Cavigliasso ◽  
Delano P Chong
Keyword(s):  
Density Functional ◽  
Binding Energies ◽  
Basis Set ◽  
Basis Sets ◽  
Density Functional Calculation ◽  
Average Absolute Deviation ◽  
Absolute Deviation ◽  
Core Electron ◽  
Electron Binding Energies ◽  
Electron Binding

Our procedure for calculating core-electron binding energies (CEBEs), based on the unrestricted generalized transition state model using B88/P86 functional, was extended to boron-containing molecules. Both unscaled (cc-pVTZ, cc-pVQZ, cc-pV5Z) and scaled (scaled-pVTZ and scaled-pVQZ) basis sets were used. The average absolute deviation from experiment for boron CEBEs with the scaled-pVTZ basis set was found to be 0.24 eV, compared to 0.23 eV for the much larger cc-pV5Z basis set.Keywords: DFT, boron, core-electron binding energies.

SUPERALKALI MOLECULES CONTAINING HALOGENOIDS

2011 ◽  
Vol 10 (02) ◽  
pp. 191-208 ◽  
Author(s):  
IWONA ANUSIEWICZ
Keyword(s):  
Green Function ◽  
Ab Initio ◽  
Molecular Orbital ◽  
Ionization Potentials ◽  
Basis Sets ◽  
Ab Initio Methods ◽  
Structure And Properties ◽  
Vertical Ionization Potentials ◽  
Outer Valence

The structure and properties of hypermetalated Li 2X and Na 2X and their corresponding Li 2X+ and Na 2X+ cations utilizing halogenoids X (SCN, OCN, and CN) were investigated using ab initio methods at the CCSD(T)/6-311+G(3df)//MP2/6-311+G(d) level of theory. The vertical ionization potentials of Li 2X and Na 2X radicals were calculated at the outer valence Green function level (OVGF) with the 6-311+G(3df) basis sets. It was found that all Na 2X molecules studied possess the vertical ionization potentials (VIP) that are smaller than the IP of the Na atom (5.14 eV) and thus may be termed superalkali molecules, whereas the Li 2X radicals exhibit slightly larger IPs. The smallest VIP of 4.728 eV was calculated for the Na 2 CN system. The IP dependence on the structure and the singly occupied molecular orbital (SOMO) character is also discussed.

scholarly journals Basis sets for the calculation of core-electron binding energies

2018 ◽  
Vol 699 ◽  
pp. 279-285 ◽  
Author(s):  
Magnus W.D. Hanson-Heine ◽  
Michael W. George ◽  
Nicholas A. Besley
Keyword(s):  
Binding Energies ◽  
Basis Sets ◽  
Core Electron ◽  
Electron Binding Energies ◽  
Electron Binding
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