The Nearly Degenerate Triplet Electronic Ground State Isomers of Lithium Nitroxide

2007 ◽  
Vol 72 (2) ◽  
pp. 129-152 ◽  
Author(s):  
Justin M. Turney ◽  
Henry F. Schaefer
Keyword(s):  
Ground State ◽  
Global Minimum ◽  
Electronic Ground State ◽  
Basis Sets ◽  
Stationary Points ◽  
Mechanical Methods ◽  
State Potential ◽  
Correlation Consistent ◽  
Highly Correlated ◽  
Electronic Ground

The triplet electronic ground state potential energy surface of lithium nitroxide has been systematically investigated using convergent quantum mechanical methods. Equilibrium structures and physical properties for five stationary points (three minima and two transition states) have been determined employing highly correlated coupled cluster theory with four correlation-consistent polarized-valence (cc-pVXZ and aug-cc-pVXZ, X = T and Q) and two core correlation-consistent polarized-valence (cc-pCVXZ, X = T and Q) basis sets. The global minimum, roughly L-shaped Li-O-N, is predicted to lie 6.5 kcal mol-1 below the linear LiON minimum and 2.4 kcal mol-1 below the linear LiON minimum. The barrier to isomerization from the global minimum to LiON was found to be 7.4 kcal mol-1 and with regard to LiNO 6.9 kcal mol-1. The dissociation energies, D0, with respect to Li + NO, have been predicted for all minima and for the global minimum was found to be 34.9 kcal mol-1.

Atomic-scale studies of chemical and transport processes relevant to propellant combustion

2018 ◽  
Author(s):  
◽  
Rezvan Chitsazi
Keyword(s):  
Ground State ◽  
Density Functional ◽  
Minimum Energy ◽  
Transport Processes ◽  
Electronic Ground State ◽  
Atomic Scale ◽  
Stationary Points ◽  
Insertion Reaction ◽  
Electronic Ground ◽  
Minimum Energy Pathway

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Density functional theory (DFT) and correlated molecular orbital electronic structure calculations were used to study the Al + CO2 [subscript arrow] AlO + CO reaction on the electronic ground-state potential-energy surface (PES). Geometries were optimized using DFT (M11/jun-cc-pV(Q+d)Z) and more accurate energies were obtained using the composite Weizmann-1 theory with Brueckner doubles (W1BD). The results comprise the most complete, most systematic characterization of the Al + CO2 reaction surface to date and are based on consistent application of high-level methods for all stationary points identified. The pathways from Al + CO[subscript 2] to AlO + CO on the electronic ground-state PES all involve formation of one or more stable AlCO2 complexes denoted ?-AlCO2, trans-AlCO[subscript 2], and C[subscript 2v]-AlCO[subscript 2], among which [subscript n]-AlCO[subscript 2] and C[subscript 2v]-AlCO[subscript 2] are the least and most stable, respectively. We report a new minimum-energy pathway for the overall reaction, namely formation of [subscript n]-AlCO[subscript 2] from reactants and dissociation of that same complex to products via a bond-insertion reaction that passes through a fourth (weakly metastable) AlCO[subscript 2] complex denoted cis-OAlCO. Natural Bond Orbital analysis was applied to study trends in charge distribution and the degree of charge transfer in key structures along the minimum-energy pathway. The process of aluminum insertion into CO[subscript 2] is discussed in the context of analogous processes for boron and first-row transition metals. ...

Simplified Non-Empirical Unrestricted Hartree-Fock Approximation (SUHF) for the Calculation of Electronic Ground State Properties of Molecules with Closed and Open Valence Shells. II. Diatomic Molecules

1993 ◽  
Vol 48 (7) ◽  
pp. 834-840
Author(s):  
Wolfhard Koch ◽  
Klaus Neymeyr ◽  
Markus Pernpointner ◽  
Barbara Schaper ◽  
Klaus Strecker
Keyword(s):  
Ground State ◽  
Diatomic Molecules ◽  
Electronic Ground State ◽  
Basis Sets ◽  
Gaussian Basis Sets ◽  
Atomic Spin ◽  
Hartree Fock ◽  
Total Energies ◽  
Simplified Procedure ◽  
Electronic Ground

Abstract A comparison of numerical Simplified Unrestricted Hartree-Fock (SUHF) results (electronic ground state configurations, total energies, first ionization potentials, atomic charges, atomic spin densities of diatomic molecules) with those of equivalent standard calculations suggests the applicability of the non-empirical but drastically simplified procedure. SUHF may even approach ab initio quality obtained with simple (STO-3G) contracted Gaussian basis sets.

New analytical model for the ozone electronic ground state potential surface and accurate ab initio vibrational predictions at high energy range

2013 ◽  
Vol 139 (13) ◽  
pp. 134307 ◽  
Author(s):  
Vladimir G. Tyuterev ◽  
Roman V. Kochanov ◽  
Sergey A. Tashkun ◽  
Filip Holka ◽  
Péter G. Szalay
Keyword(s):  
Energy Range ◽  
Ab Initio ◽  
Analytical Model ◽  
Ground State ◽  
Potential Surface ◽  
High Energy ◽  
Electronic Ground State ◽  
State Potential ◽  
Electronic Ground

Correlation, Relativistic and Adiabatic Corrections to the Ground State Potential Curve of the Hydrogen Molecule

2000 ◽  
Vol 65 (9) ◽  
pp. 1387-1393
Author(s):  
Ján Micanko ◽  
Stanislav Biskupič ◽  
Martina Bittererová
Keyword(s):  
Wave Function ◽  
Ab Initio ◽  
Numerical Solution ◽  
Ground State ◽  
Hydrogen Molecule ◽  
Basis Sets ◽  
State Potential ◽  
Component Wave ◽  
Electronic Ground ◽  
Good Agreement

Correlation, relativistic and adiabatic corrections are computed for the electronic ground state of the hydrogen molecule for r ≤ 12 a.u. In contrast to previous calculations (based on the numerical solution of the Schrödinger equation, mainly done by Wolniewicz et al.), our results are based on the ordinary ab initio treatment using a four-component wave function with fully relativistically reoptimized basis sets and adiabatic corrections by the treatment developed in our laboratory. The calculated energies are fitted to the polynomial/exponential analytical function and the evaluated spectroscopic parameters are compared with those obtained in the same manner from the Wolniewicz data. The results presented show a good agreement with exact numerical calculations published previously.

ChemInform Abstract: TRIPLET ELECTRONIC GROUND STATE OF TRIMETHYLENEMETHANE

1974 ◽  
Vol 5 (33) ◽  
pp. no-no
Author(s):  
DAVID R. YARKONY ◽  
HENRY F. III SCHAEFER
Keyword(s):  
Ground State ◽  
Electronic Ground State ◽  
Electronic Ground

Consistent characterization of the electronic ground state of Iron (II) Phthalocyanine from valence and core-shell electron spectroscopy

2021 ◽  
Author(s):  
Jonathan Laurent ◽  
John Bozek ◽  
Marc BRIANT ◽  
Pierre Carcabal ◽  
Denis Cubaynes ◽  
...  
Keyword(s):  
Gas Phase ◽  
Ground State ◽  
Electron Spectroscopy ◽  
Organometallic Compound ◽  
Electronic Ground State ◽  
Core Shell ◽  
Shell Electron ◽  
Phthalocyanine Molecule ◽  
Electronic Ground

We studied the Iron (II) Phthalocyanine molecule in the gas-phase. It is a complex transition organometallic compound, for which, the characterization of its electronic ground state is still debated more...

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