scholarly journals Energy decomposition analysis for exciplexes using absolutely localized molecular orbitals

2018 ◽  
Vol 148 (6) ◽  
pp. 064105 ◽  
Author(s):  
Qinghui Ge ◽  
Yuezhi Mao ◽  
Martin Head-Gordon
Keyword(s):  
Decomposition Analysis ◽  
Molecular Orbitals ◽  
Energy Decomposition Analysis ◽  
Energy Decomposition ◽  
Localized Molecular Orbitals

scholarly journals Energy Decomposition Analysis Method for Metallic Systems

2021 ◽  
Author(s):  
Han Chen ◽  
Chris-Kriton Skylaris
Keyword(s):  
Decomposition Analysis ◽  
Molecular Orbitals ◽  
Energy Decomposition Analysis ◽  
Analysis Method ◽  
Energy Decomposition ◽  
Localized Molecular Orbitals ◽  
Metallic Systems

In this work, we present the first extension of an energy decomposition analysis (EDA) method to metallic systems. We extend the theory of our Hybrid Absolutely Localized Molecular Orbitals (HALMO)...

scholarly journals Probing non-covalent interactions with a second generation energy decomposition analysis using absolutely localized molecular orbitals

2016 ◽  
Vol 18 (33) ◽  
pp. 23067-23079 ◽  
Author(s):  
Paul R. Horn ◽  
Yuezhi Mao ◽  
Martin Head-Gordon
Keyword(s):  
Second Generation ◽  
Decomposition Analysis ◽  
Molecular Orbitals ◽  
Energy Decomposition Analysis ◽  
Analysis Method ◽  
Energy Decomposition ◽  
Localized Molecular Orbitals ◽  
Non Covalent Interactions ◽  
Covalent Interactions

Second generation of variational energy decomposition analysis method based on absolutely localized molecular orbitals.

scholarly journals Variational Forward-Backward Charge Transfer Analysis Based on Absolutely Localized Molecular Orbitals: Energetics and Molecular Properties

2019 ◽  
Author(s):  
Matthias Loipersberger ◽  
Yuezhi Mao ◽  
Martin Head-Gordon
Keyword(s):  
Charge Transfer ◽  
Lewis Acids ◽  
Decomposition Analysis ◽  
Blue Shift ◽  
Molecular Orbitals ◽  
Energy Decomposition Analysis ◽  
Intermolecular Distance ◽  
Nuclear Forces ◽  
Localized Molecular Orbitals ◽  
Back Donation

<div> <div> <div> <p>To facilitate the understanding of charge transfer (CT) effects in dative complexes, we propose a variational forward-backward (VFB) approach to decompose the overall CT stabilization energy into contributions from forward and backward donation in the framework of energy decomposition analysis based on absolutely localized molecular orbitals (ALMO-EDA). Such a decomposition is achieved by introducing two additional constrained intermediate states in which only one direction of CT is permitted. These two “one-way” CT states are variationally relaxed such that the associated nuclear forces can be readily obtained. This allows for a facile integration into the previously developed adiabatic EDA scheme so that the molecular property changes arising from forward and back donation can be separately assigned. Using ALMO-EDA augmented by this VFB model, we investigate the energetic, geometric, and vibrational features of complexes composed of CO and main group Lewis acids (BH3, BeO/BeCO3), and complexes of the N2, CO, and BF isoelectronic series with [Ru(II)(NH3)5]2+. We identify that the shift in the stretching frequency of a diatomic π-acidic ligand (XY), such as CO, results from a superposition of the shifts induced by permanent electrostatics and backward CT: permanent electrostatics can cause an either red or blue shift depend- ing on the alignment of the XY dipole in the dative complex, and this effect becomes more pronounced with a more polar XY ligand; the back-donation to the antibonding π orbital of XY always lowers the X−Y bond order and thus red-shifts its stretching frequency, and the strength of this interaction decays rapidly with the intermolecular distance. We also reveal that while σ forward donation contributes significantly to energetic stabilization, it affects the vibrational feature of XY mainly by shortening the intermolecular distance, which enhances both the electrostatic interaction and back- ward CT but in different rates. The synergistic effect of the forward and backward donations appears to be more significant in the transition metal complexes, where the forward CT plays an essential role in overcoming the strong Pauli repulsion. These findings highlight that the shift in the XY stretching frequency is not a reliable metric for the strength of π back-donation. Overall, the VFB-augmented EDA scheme that we propose and apply in this work provides a useful tool to characterize the role played by each physical component that all together lead to the frequency shift observed. </p> </div> </div> </div>

scholarly journals Consistent Inclusion of Continuum Solvation in Energy Decomposition Analysis: Theory and Application to Molecular CO2 Reduction Catalysts

2020 ◽  
Author(s):  
Yuezhi Mao ◽  
Matthias Loipersberger ◽  
Kareesa Kron ◽  
Jeffrey Derrick ◽  
Christopher Chang ◽  
...  
Keyword(s):  
Intermolecular Interactions ◽  
Chemical Reactivity ◽  
Decomposition Analysis ◽  
Substituent Effects ◽  
Co2 Reduction ◽  
Energy Decomposition Analysis ◽  
Energy Decomposition ◽  
Coulombic Interaction ◽  
Model Complexes ◽  
Localized Molecular Orbitals

<p>To facilitate computational investigation of intermolecular interactions in the solution phase, we report the development of ALMO-EDA(solv), a scheme that allows the application of continuum solvent models within the framework of energy decomposition analysis (EDA) based on absolutely localized molecular orbitals (ALMOs). In this scheme, all the quantum mechanical states involved in the variational EDA procedure are computed with the presence of solvent environment so that solvation effects are incorporated in the evaluation of all its energy components. After validation on several model complexes, we employ ALMO-EDA(solv) to investigate substituent effects on two classes of complexes that are related to electrochemical CO<sub>2</sub> reduction catalysis. For [FeTPP(CO<sub>2</sub>−κC)]<sup>2−</sup> (TPP = tetraphenylporphyrin), we reveal that two ortho substituents which yield most favorable CO2 binding, −N(CH<sub>3</sub>)<sub>3</sub><sup>+</sup> (TMA) and −OH, stabilize the complex via through-structure and through-space mechanisms, respectively. The Coulombic interaction between the positively charged TMA group and activated CO<sub>2</sub> is found to be largely attenuated by the polar solvent. Furthermore, we also provide computational support for the design strategy of utilizing bulky, flexible ligands to stabilize activated CO<sub>2</sub> via long-range Coulomb interactions, which creates biomimetic solvent-inaccessible “pockets” in that electrostatics is unscreened. For the reactant and product complexes associated with the electron transfer from the <i>p</i>-terphenyl radical anion to CO<sub>2</sub> , we demonstrate that the double terminal substitution of <i>p</i>-terphenyl by electron-withdrawing groups considerably strengthens the binding in the product state while moderately weakens that in the reactant state, which are both dominated by the substituent tuning of the electrostatics component. These applications illustrate that this new extension of ALMO-EDA provides a valuable means to unravel the nature of intermolecular interactions and quantify their impacts on chemical reactivity in solution.<br></p>

scholarly journals Variational Forward-Backward Charge Transfer Analysis Based on Absolutely Localized Molecular Orbitals: Energetics and Molecular Properties

2019 ◽  
Author(s):  
Matthias Loipersberger ◽  
Yuezhi Mao ◽  
Martin Head-Gordon
Keyword(s):  
Charge Transfer ◽  
Lewis Acids ◽  
Decomposition Analysis ◽  
Blue Shift ◽  
Molecular Orbitals ◽  
Energy Decomposition Analysis ◽  
Intermolecular Distance ◽  
Nuclear Forces ◽  
Localized Molecular Orbitals ◽  
Back Donation

<div> <div> <div> <p>To facilitate the understanding of charge transfer (CT) effects in dative complexes, we propose a variational forward-backward (VFB) approach to decompose the overall CT stabilization energy into contributions from forward and backward donation in the framework of energy decomposition analysis based on absolutely localized molecular orbitals (ALMO-EDA). Such a decomposition is achieved by introducing two additional constrained intermediate states in which only one direction of CT is permitted. These two “one-way” CT states are variationally relaxed such that the associated nuclear forces can be readily obtained. This allows for a facile integration into the previously developed adiabatic EDA scheme so that the molecular property changes arising from forward and back donation can be separately assigned. Using ALMO-EDA augmented by this VFB model, we investigate the energetic, geometric, and vibrational features of complexes composed of CO and main group Lewis acids (BH3, BeO/BeCO3), and complexes of the N2, CO, and BF isoelectronic series with [Ru(II)(NH3)5]2+. We identify that the shift in the stretching frequency of a diatomic π-acidic ligand (XY), such as CO, results from a superposition of the shifts induced by permanent electrostatics and backward CT: permanent electrostatics can cause an either red or blue shift depend- ing on the alignment of the XY dipole in the dative complex, and this effect becomes more pronounced with a more polar XY ligand; the back-donation to the antibonding π orbital of XY always lowers the X−Y bond order and thus red-shifts its stretching frequency, and the strength of this interaction decays rapidly with the intermolecular distance. We also reveal that while σ forward donation contributes significantly to energetic stabilization, it affects the vibrational feature of XY mainly by shortening the intermolecular distance, which enhances both the electrostatic interaction and back- ward CT but in different rates. The synergistic effect of the forward and backward donations appears to be more significant in the transition metal complexes, where the forward CT plays an essential role in overcoming the strong Pauli repulsion. These findings highlight that the shift in the XY stretching frequency is not a reliable metric for the strength of π back-donation. Overall, the VFB-augmented EDA scheme that we propose and apply in this work provides a useful tool to characterize the role played by each physical component that all together lead to the frequency shift observed. </p> </div> </div> </div>

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