Stable Positions of a Metal Ion Relative to an Icosahedral Borane

1987 ◽  
Vol 97 ◽  
Author(s):  
C. L. Beckel ◽  
I. A. Howard
Keyword(s):  
Molecular Orbital ◽  
Ionization Energy ◽  
Metal Ion ◽  
Basis Set ◽  
Molecular Orbital Calculations ◽  
Neutral Complex ◽  
Self Consistent ◽  
Cluster Energy

ABSTRACTWe have considered a series of conformations of the neutral complex [Mg+B12H12] including those in which the Mg is internal to the icosahedral B12 cage. Self-consistent molecular-orbital calculations to determine the total cluster energy have been carried out as the Mg atom is moved from the center of the borane to a position 10Å from the center (outside the borane cage). Two energy minima are found as a function of position. One is outside the borane cage. at 3.0–3.5Å from the center; the second is at the center of the borane cage. The central minimum is the deeper of the two if Mg 3d orbitals are included in the basis set.Many atoms have a low ionization energy and are, as ions, of appropriate “size” to fit inside a B12 cage. Incorporation of such ions into B12 cages in solids may offer significant flexibility in the development of refractory semiconductors and thermoelectrics.

The Photoelectron Spectrum of 1-Bromonortricyclene

1985 ◽  
Vol 38 (1) ◽  
pp. 69 ◽  
Author(s):  
EW Della ◽  
PE Pigou ◽  
MK Livett ◽  
JB Peel
Keyword(s):  
Energy Range ◽  
Ab Initio ◽  
Molecular Orbital ◽  
Density Of States ◽  
Ionization Energy ◽  
Photoelectron Spectrum ◽  
Valence Electron ◽  
Alkyl Halide ◽  
High Density ◽  
Molecular Orbital Calculations

The He I photoelectron spectrum of 1-bromotricyclo[2.2.1.02.6] heptane (1- bromonortricyclene ) is compared with that of the parent alkane . Extensive conjugation between bromine and alkane orbitals in the low ionization-energy range produces a complex band pattern which is adequately described by ab initio valence-electron molecular orbital calculations. Consequently 1-bromo-nortricyclene presents a rare example of an alkyl halide in which the halogen character is neither highly localized nor smeared over a high density of states.

Ab initio molecular orbital calculations of the ground and excited states of the permanganate and chromate ions

1970 ◽  
Vol 320 (1541) ◽  
pp. 161-173 ◽  
Keyword(s):  
Molecular Orbital ◽  
Excited States ◽  
Slater Type Orbitals ◽  
Molecular Orbital Calculations ◽  
Field Equations ◽  
Chromate Ions ◽  
Consistent Field ◽  
Self Consistent ◽  
Self Consistent Field ◽  
State Wavefunctions

The bonding in the permanganate and chromate ions is described by means of self-consistent field molecular orbital calculations employing a basis of Slater type orbitals expanded in Gaussian type functions. A new procedure for the solution of the self-consistent field equations is described and applied to the ions studied here. Excited state wavefunctions are calculated using configuration interaction considering all singly excited configurations involving all virtual and valence orbitals. The calculated transition energies and transition moments are compared with those from the experimental electronic spectra.

Protonation Effect on C-N Bond Length of Alkylamines Studied by Molecular Orbital Calculations

2000 ◽  
Vol 55 (9-10) ◽  
pp. 769-771 ◽  
Keyword(s):  
Density Functional Theory ◽  
Bond Length ◽  
Molecular Orbital ◽  
Density Functional ◽  
Second Order ◽  
Basis Set ◽  
Molecular Orbital Calculations ◽  
Functional Theory ◽  
Hartree Fock ◽  
Protonation Effect

Abstract Molecular orbital calculations were performed for the six saturated alkylamines (CH3NH2 , (CH3)2 NH, (CH 3)3 N, CH 3CH2NH2 , (CH3)2 CHNH2 , (CH3)3 CNH2), their protonated cations (CH3NH3 + , (CH3)2NH2 + , (CH3)3NH + , CH3CH2NH3 + , (CH3)2CHNH3 + , (CH3)3CNH3+), and (CH3)4 N + using the Hartree-Fock, second-order M0ller-Plesset, and density functional theory methods with the 6-311+G(d,p) basis set. Protonation lengthens the C-N bonds of the amines by 0.05 -0.08 Å and shortens the C-C bonds of CH3CH2NH2, (CH3)2CHNH2 , and (CH3)3CNH2 by ca. 0.01 Å.

Structures of simple anions from ab initio molecular orbital calculations

1976 ◽  
Vol 29 (8) ◽  
pp. 1635 ◽  
Author(s):  
L Radom
Keyword(s):  
Ab Initio ◽  
Molecular Orbital ◽  
Basis Set ◽  
Basis Sets ◽  
Molecular Orbital Calculations ◽  
Limited Information ◽  
Orbital Theory ◽  
Comparable Quality ◽  
Split Valence ◽  
Theoretical Results

Ab initio molecular orbital theory with the minimal STO-3G and split-valence 4-31G basis sets is used to obtain geometries of 18 anions:OH-, NH2-, HF2-, BH4-, BF4-, C22-, CN-, NCN2-, N3-, NO2-, NO3-, 0CCO2-, CO32-, HCOO-, CH3COO-, C2O42-, C4O42- and C(CN)3-. The theoretical results are compared with experimental results from the literature. The STO-3G basis set performs somewhat worse for anions than for neutral molecules. On the other hand, the 4-31G basis set gives good results and predicts bond lengths to within 0.02� for all the molecules considered. Limited information on bond angle predictions suggests that these are of comparable quality to those for neutral molecules. The tricyanomethanide ion is predicted to be planar.

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