The effects of basis set quality and configuration mixing in ab initio calculations of the ionization potentials of the nitrogen molecule

1980 ◽  
Vol 73 (5) ◽  
pp. 2297-2303 ◽  
Author(s):  
W. C. Ermler ◽  
A. D. McLean
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
Nitrogen Molecule ◽  
Ionization Potentials ◽  
Basis Set ◽  
Configuration Mixing

The electronic structures, geometries, and relative energies of some N2H2 and N2H2+ systems

1977 ◽  
Vol 55 (2) ◽  
pp. 350-354 ◽  
Author(s):  
N. Colin Baird ◽  
David A. Wernette
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
Configuration Interaction ◽  
Electronic Structures ◽  
Ground States ◽  
Heat Of Formation ◽  
Ionization Potentials ◽  
Basis Set ◽  
Relative Stabilities ◽  
Positive Ions

Ab initio calculations using the 4-31G basis set and extensive configuration interaction are reported for the 1Ag state of trans-diimide (1), the 3A″ and 1A1 states of 1,1-dihydrodiazine (2), and the ground states of the positive ions of these systems and of cis-diimide. In all cases the geometries have been optimized. The relative stabilities of these systems are discussed, with particular reference to the heat of formation of trans-1 and to the ionization potentials of 1 and 2.

Vicinal proton—proton coupling constants. Basis set dependence in SCF ab initio calculations

1993 ◽  
Vol 206 (1-4) ◽  
pp. 253-259 ◽  
Author(s):  
Jesús San-Fabián ◽  
Joaquín Guilleme ◽  
Ernesto Díez ◽  
Paolo Lazzeretti ◽  
Massimo Malagoli ◽  
...  
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
Coupling Constants ◽  
Basis Set ◽  
Proton Proton ◽  
Proton Coupling ◽  
Vicinal Proton

scholarly journals Geometric and Energetic Data from Ab Initio Calculations of Haloethene, Haloimine, Halomethylphosphine, Haloiminophosphine, Halodiazene, Halodiphosphene and Halocyclopropane

2019 ◽  
Author(s):  
Kridtin Chinsukserm ◽  
Wanutcha Lorpaiboon ◽  
Peerayar Teeraniramitr ◽  
Taweetham Limpanuparb
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
Quantum Chemical ◽  
Theoretical Data ◽  
Geometric Optimization ◽  
Basis Set ◽  
Halogenated Compounds ◽  
Wolfram Mathematica

<p>This article presents theoretical data on geometric and energetic features of halogenated compounds of cyclopropane (∆) and ethene (C=C), imine (C=N), methylphosphine (C=P), iminophosphine (N=P), diazene (N=N) and diphosphene (P=P). The data were obtained from <i>ab initio</i> geometric optimization and frequency calculations at HF, B3LYP, MP2 and CCSD levels of theory on 6-311++G(d,p) basis set. Input structures were generated by shell scripts and run by Q-Chem quantum chemical package. The output files were processed to extract geometric and energetic information by Wolfram Mathematica.</p>

Conformational Structure of Chloromethyldichlorophosphines

2002 ◽  
Vol 57 (6-7) ◽  
pp. 333-336
Author(s):  
Evgenii A. Romanenko ◽  
Alexander M. Nesterenko
Keyword(s):  
Experimental Data ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Electron Correlation ◽  
Basis Set ◽  
Conformational Structure ◽  
Gauche Conformation ◽  
Nuclear Quadrupole ◽  
Set Up ◽  
Good Agreement

IThe 35Cl nuclear quadrupole resonances (77 K) and ab initio calculations of trichloromethyldichlorophosphine () show that it exists in the chess conformation form. The barrier to internal rotation about the P-C bond in I at the RHF/6-31++ G(d,p) level equals to 38.1 kJ mol-1. In chloromethyldichlorophosphine (II) the extension of the basis set up to the RHF/6-311++G(df, pd) level does not improve the description of the most preferable gauche-conformation; only if electron correlation (at the MP2 level) is taken into account the results are in a good agreement with experimental data.

Some ab Initio Calculations on Indole, Isoindole, Benzofuran, and Isobenzofuran

1974 ◽  
Vol 29 (4) ◽  
pp. 624-632 ◽  
Author(s):  
J. Koller ◽  
A. Ažman ◽  
N. Trinajstić
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
Chemical Shifts ◽  
Dipole Moments ◽  
Molecular Properties ◽  
Ionization Potentials ◽  
Charge Densities ◽  
Homo Lumo

Ab initio calculations in the framework of the methodology of Pople et al. have been performed on indole, isoindole, benzofuran. and isobenzofuran. Several molecular properties (dipole moments, n. m. r. chemical shifts, stabilities, and reactivities) correlate well with calculated indices (charge densities, HOMO-LUMO separation). The calculations failed to give magnitudes of first ionization potentials, although the correct trends are reproduced, i. e. giving higher values to more stable isomers. Some of the obtained results (charge densities, dipole moments) parallel CNDO/2 values.

On the tautomerism of 1-phenyl-3-substituted-pyrazol-5-ones and their photoinduced products — experimental and theoretical UV spectral analysis

2008 ◽  
Vol 62 (3) ◽  
Author(s):  
Atanas Chapkanov ◽  
Bojidarka Koleva ◽  
Michail Arnaudov ◽  
Ivan Petkov
Keyword(s):  
Spectral Analysis ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Uv Spectra ◽  
Basis Set ◽  
Geometrical Parameters ◽  
Tautomeric Forms

AbstractA detailed experimental and theoretical UV-spectral analysis of the tautomeric forms of 3-methyl-1-phenyl pyrazol-5-one and 1,3-diphenyl pyrazol-5-one as well as of the UV-irradiated photoinduced products of the latter compound were carried out. The experimental UV-spectra were compared with the theoretical ones obtained by CIS/6-31G**. Selected geometrical parameters of the different tautomers were estimated by ab initio calculations using the RHF/6-31G** level of theory and basis set, which have also been discussed with a view to the corresponding UV-results.

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