Optimized Gaussian basis set for second row transition metals

1982 ◽  
Vol 77 (4) ◽  
pp. 1921-1929 ◽  
Author(s):  
Marvin E. Friedlander ◽  
James M. Howell ◽  
Grace Snyder
Keyword(s):  
Transition Metals ◽  
Basis Set ◽  
Gaussian Basis Set

scholarly journals Benchmarking the Fluxional Processes of Organometallic Piano-Stool Complexes

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2310
Author(s):  
Nathan C. Frey ◽  
Eric Van Dornshuld ◽  
Charles Edwin Webster
Keyword(s):  
Transition Metals ◽  
Density Functional ◽  
Chemical Shifts ◽  
Transition States ◽  
Electronic Energy ◽  
Basis Set ◽  
Composite Approach ◽  
Temperature Regimes ◽  
Correlation Consistent Composite Approach ◽  
Correlation Consistent

The correlation consistent Composite Approach for transition metals (ccCA-TM) and density functional theory (DFT) computations have been applied to investigate the fluxional mechanisms of cyclooctatetraene tricarbonyl chromium ((COT)Cr(CO)3) and 1,3,5,7-tetramethylcyclooctatetraene tricarbonyl chromium, molybdenum, and tungsten ((TMCOT)M(CO)3 (M = Cr, Mo, and W)) complexes. The geometries of (COT)Cr(CO)3 were fully characterized with the PBEPBE, PBE0, B3LYP, and B97-1 functionals with various basis set/ECP combinations, while all investigated (TMCOT)M(CO)3 complexes were fully characterized with the PBEPBE, PBE0, and B3LYP methods. The energetics of the fluxional dynamics of (COT)Cr(CO)3 were examined using the correlation consistent Composite Approach for transition metals (ccCA-TM) to provide reliable energy benchmarks for corresponding DFT results. The PBE0/BS1 results are in semiquantitative agreement with the ccCA-TM results. Various transition states were identified for the fluxional processes of (COT)Cr(CO)3. The PBEPBE/BS1 energetics indicate that the 1,2-shift is the lowest energy fluxional process, while the B3LYP/BS1 energetics (where BS1 = H, C, O: 6-31G(d′); M: mod-LANL2DZ(f)-ECP) indicate the 1,3-shift having a lower electronic energy of activation than the 1,2-shift by 2.9 kcal mol−1. Notably, PBE0/BS1 describes the (CO)3 rotation to be the lowest energy process, followed by the 1,3-shift. Six transition states have been identified in the fluxional processes of each of the (TMCOT)M(CO)3 complexes (except for (TMCOT)W(CO)3), two of which are 1,2-shift transition states. The lowest-energy fluxional process of each (TMCOT)M(CO)3 complex (computed with the PBE0 functional) has a ΔG‡ of 12.6, 12.8, and 13.2 kcal mol−1 for Cr, Mo, and W complexes, respectively. Good agreement was observed between the experimental and computed 1H-NMR and 13C-NMR chemical shifts for (TMCOT)Cr(CO)3 and (TMCOT)Mo(CO)3 at three different temperature regimes, with coalescence of chemically equivalent groups at higher temperatures.

Formulation of theLCAS MS SCF method within the Gaussian basis set

1980 ◽  
Vol 18 (1) ◽  
pp. 65-71 ◽  
Author(s):  
Szczepan Roszak ◽  
Henryk Chojnacki
Keyword(s):  
Basis Set ◽  
Gaussian Basis Set

Highly accurate relativistic universal Gaussian basis set for Dirac-Fock-Breit calculations

2005 ◽  
Vol 102 (1) ◽  
pp. 1-7 ◽  
Author(s):  
L. G. M. De Macedo ◽  
R. C. Barbosa ◽  
A. B. F. da Silva
Keyword(s):  
Basis Set ◽  
Gaussian Basis Set

A Systematic abinitio LCAO–MO–SCF Study of the Ionization Potentials, Electron, Proton, Hydrogen, and Hydride Affinities of SHn Molecules and Ions

1975 ◽  
Vol 53 (24) ◽  
pp. 3747-3756 ◽  
Author(s):  
Roy E. Kari ◽  
Imre G.A Csizmadia
Keyword(s):  
Ionization Potentials ◽  
Basis Set ◽  
Charged Species ◽  
Polarization Functions ◽  
Gaussian Basis Set ◽  
Equilibrium Geometries ◽  
Lcao Mo

Equilibrium geometries and energies are obtained for SHn (n = 0, 1, 2, 3) neutral and charged species by the Roothaan LCAO–MO–SCF method. A large gaussian basis set including d and p polarization functions was employed. The calculated ionization potentials, electron, proton, hydrogen, and hydride affinities are discussed as well as compared with similar previously calculated properties for OHn (n = 0, 1, 2, 3) species.

Universal Gaussian basis functions in relativistic quantum chemistry: atomic Dirac–Fock–Coulomb and Dirac–Fock–Breit calculations

1992 ◽  
Vol 70 (6) ◽  
pp. 1822-1826 ◽  
Author(s):  
G. L. Malli ◽  
A. B. F. Da Silva ◽  
Yasuyuki Ishikawa
Keyword(s):  
Relativistic Quantum ◽  
Basis Set ◽  
Basis Sets ◽  
Interaction Energies ◽  
Gaussian Basis Sets ◽  
Consistent Field ◽  
Self Consistent ◽  
Self Consistent Field ◽  
Gaussian Basis Set ◽  
Good Agreement

Matrix Dirac–Fock–Coulomb and Dirac–Fock–Breit self-consistent field calculations are performed for a number of neutral atoms. He (Z = 2) through Xe (Z = 54), using the universal Gaussian basis set (18s, 12p, 11d) reported recently by Da Silva etal. The total Dirac–Fock–Coulomb, the Dirac–Fock–Breit, and the Breit interaction energies calculated with this universal Gaussian basis set are in good agreement with the corresponding values obtained by using an extensive well-tempered Gaussian basis set for the He through Ca (Z = 20) atoms. Although this universal Gaussian basis set is inadequate for the calculation of total Dirac–Fock–Coulomb and Dirac–Fock–Breit energies for the Kr, Sr, and Xe atoms, the Breit interaction energies calculated with this basis for these three atoms are in very good agreement with the corresponding Breit interaction energies obtained by using the extensive well-tempered Gaussian basis sets. Work is in progress to generate a more extensive and energetically better universal Gaussian basis set for He through Xe for its use in non-relativistic Hartree–Fock as well as Dirac–Fock self-consistent field calculations on polyatomics involving heavy atoms.

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