Molecular-orbital and empirical-potential descriptions of CaCO3

1998 ◽  
Vol 94 (18) ◽  
pp. 2653-2661 ◽  
Author(s):  
Dennis J. Thackeray ◽  
Paul D. Siders
Keyword(s):  
Molecular Orbital ◽  
Empirical Potential

MOLECULAR ORBITAL CALCULATION ON THE INTERSTITIAL CARBON IN STEEL MARTENSITE

1982 ◽  
Vol 43 (C4) ◽  
pp. C4-103-C4-108 ◽  
Author(s):  
F. E. Fujita ◽  
S. Nasu ◽  
H. Adachi
Keyword(s):  
Molecular Orbital ◽  
Molecular Orbital Calculation ◽  
Interstitial Carbon

Interactions between Methylene Blue and Pullulan According to Molecular Orbital Calculations

2020 ◽  
Vol 140 (11) ◽  
pp. 529-533
Author(s):  
Pasika Temeepresertkij ◽  
Saranya Yenchit ◽  
Michio Iwaoka ◽  
Satoru Iwamori
Keyword(s):  
Methylene Blue ◽  
Molecular Orbital ◽  
Molecular Orbital Calculations

Parallel Fock Matrix Construction Algorithm for Molecular Orbital Calculation Specific Computer

2006 ◽  
Vol 5 (1) ◽  
pp. 179-188
Author(s):  
Hiroaki UMEDA ◽  
Yuichi INADOMI ◽  
Hiroaki HONDA ◽  
Umpei NAGASHIMA
Keyword(s):  
Molecular Orbital ◽  
Molecular Orbital Calculation ◽  
Construction Algorithm ◽  
Matrix Construction

Resolving the Quadruple Bonding Conundrum in C2 Using Insights Derived from Excited State Potential Energy Surfaces: A Molecular Orbital Perspective

2019 ◽  
Author(s):  
Ishita Bhattacharjee ◽  
Debashree Ghosh ◽  
Ankan Paul
Keyword(s):  
Excited State ◽  
Potential Energy ◽  
Molecular Orbital ◽  
High Spin ◽  
Potential Energy Surfaces ◽  
Valence Bond ◽  
Deep Minimum ◽  
State Potential ◽  
Energy Surfaces ◽  
Mo Theory

The question of quadruple bonding in C<sub>2</sub> has emerged as a hot button issue, with opinions sharply divided between the practitioners of Valence Bond (VB) and Molecular Orbital (MO) theory. Here, we have systematically studied the Potential Energy Curves (PECs) of low lying high spin sigma states of C<sub>2</sub>, N<sub>2</sub> and Be<sub>2</sub> and HC≡CH using several MO based techniques such as CASSCF, RASSCF and MRCI. The analyses of the PECs for the<sup> 2S+1</sup>Σ<sub>g/u</sub> (with 2S+1=1,3,5,7,9) states of C<sub>2</sub> and comparisons with those of relevant dimers and the respective wavefunctions were conducted. We contend that unlike in the case of N<sub>2</sub> and HC≡CH, the presence of a deep minimum in the <sup>7</sup>Σ state of C<sub>2</sub> and CN<sup>+</sup> suggest a latent quadruple bonding nature in these two dimers. Hence, we have struck a reconciliatory note between the MO and VB approaches. The evidence provided by us can be experimentally verified, thus providing the window so that the narrative can move beyond theoretical conjectures.

Radical Enzymes Control the Chemistry of Their Highly Reactive Intermediates Using the Quantum Coulombic Effect

2020 ◽  
Author(s):  
Hossein Khalilian ◽  
Gino A. DiLabio
Keyword(s):  
Hydrogen Bonding ◽  
Molecular Orbital ◽  
Reactive Intermediates ◽  
Hydrogen Bonding Interaction ◽  
Orbital Ordering ◽  
Dynamic Nature ◽  
Radical Intermediate ◽  
Highest Occupied Molecular Orbital ◽  
Bonding Interaction ◽  
Close Proximity

Here, we report an exquisite strategy that the B12 enzymes exploit to manipulate the reactivity of their radical intermediate (Adenosyl radical). Based on the quantum-mechanic calculations, these enzymes utilize a little known long-ranged through space quantum Coulombic effect (QCE). The QCE causes the radical to acquire an electronic structure that contradicts the Aufbau Principle: The singly-occupied molecular orbital (SOMO) is no longer the highest-occupied molecular orbital (HOMO) and the radical is unable to react with neighbouring substrates. The dynamic nature of the enzyme and its structure is expected to be such that the reactivity of the radical is not restored until it is moved into close proximity of the target substrate. We found that the hydrogen bonding interaction between the nearby conserved glutamate residue and the ribose ring of Adenosyl radical plays a crucial role in manipulating the orbital ordering

Radical Enzymes Control the Chemistry of Their Highly Reactive Intermediates Using the Quantum Coulombic Effect

2020 ◽  
Author(s):  
Hossein Khalilian ◽  
Gino A. DiLabio
Keyword(s):  
Hydrogen Bonding ◽  
Molecular Orbital ◽  
Reactive Intermediates ◽  
Hydrogen Bonding Interaction ◽  
Orbital Ordering ◽  
Dynamic Nature ◽  
Radical Intermediate ◽  
Highest Occupied Molecular Orbital ◽  
Bonding Interaction ◽  
Close Proximity

Here, we report an exquisite strategy that the B12 enzymes exploit to manipulate the reactivity of their radical intermediate (Adenosyl radical). Based on the quantum-mechanic calculations, these enzymes utilize a little known long-ranged through space quantum Coulombic effect (QCE). The QCE causes the radical to acquire an electronic structure that contradicts the Aufbau Principle: The singly-occupied molecular orbital (SOMO) is no longer the highest-occupied molecular orbital (HOMO) and the radical is unable to react with neighbouring substrates. The dynamic nature of the enzyme and its structure is expected to be such that the reactivity of the radical is not restored until it is moved into close proximity of the target substrate. We found that the hydrogen bonding interaction between the nearby conserved glutamate residue and the ribose ring of Adenosyl radical plays a crucial role in manipulating the orbital ordering

Sign in / Sign up

Export Citation Format

Share Document