scholarly journals Hartree–Fock orbitals significantly improve the reaction barrier heights predicted by semilocal density functionals

2008 ◽  
Vol 128 (24) ◽  
pp. 244112 ◽  
Author(s):  
Benjamin G. Janesko ◽  
Gustavo E. Scuseria
Keyword(s):  
Density Functionals ◽  
Reaction Barrier ◽  
Hartree Fock ◽  
Barrier Heights

scholarly journals The crystalline structure of SrRuO3: Application of hybrid scheme to the density functionals revised for solids

2017 ◽  
Vol 57 (2) ◽  
Author(s):  
Šarūnas Masys ◽  
Valdas Jonauskas
Keyword(s):  
Crystalline Structure ◽  
Density Functional ◽  
Theoretical Modelling ◽  
Density Functionals ◽  
Hybrid Scheme ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Hartree Fock ◽  
Hybrid Density Functional ◽  
Theory Scheme

The crystalline structure of ground-state orthorhombic SrRuO3 is reproduced by applying the hybrid density functional theory scheme to the functionals based on the revised generalized-gradient approximations for solidstate calculations. The amount of Hartree–Fock (HF) exchange energy is varied in the range of 5–20% in order to systematically ascertain the optimum value of HF mixing which in turn ensures the best correspondence to the experimental measurements. Such investigation allows one to expand the set of tools that could be used for the efficient theoretical modelling of, for example, only recently stabilized phases of SrRuO3, helping to resolve issues emerging for the experimentalists.

Hartree-Fock energy-density functionals generated by local-scaling transformations: Applications to first-row atoms

1997 ◽  
Vol 107 (17) ◽  
pp. 6722-6731 ◽  
Author(s):  
R. López-Boada ◽  
E. V. Ludeña ◽  
V. Karasiev ◽  
R. Pino
Keyword(s):  
Energy Density ◽  
Density Functionals ◽  
Local Scaling ◽  
Hartree Fock

Experimental and Theoretical Studies of Rotational Barriers in Aceto-, N-Methylaceto- and N-Phenylacetohydroxamic Acid

2001 ◽  
Vol 66 (1) ◽  
pp. 99-108 ◽  
Author(s):  
David A. Brown ◽  
Laurence P. Cuffe ◽  
Geraldine M. Fitzpatrick ◽  
Noel J. Fitzpatrick ◽  
William K. Glass ◽  
...  
Keyword(s):  
Gas Phase ◽  
Density Functional ◽  
Theoretical Calculations ◽  
Zero Point ◽  
Density Functional Theory Calculations ◽  
Point Energy ◽  
Hartree Fock ◽  
Barrier Heights ◽  
Rotational Barriers ◽  
Moller Plesset

Experimental and theoretical calculations for the E and Z forms of aceto-, N-methylaceto- and N-phenylacetohydroxamic acid are reported. The experimental method was NMR spectroscopy, while the computational methods included Hartree-Fock, Møller-Plesset and density functional theory calculations, with and without solvation, using either the Onsager or Tomasi's PCM method. In all calculations zero point energy corrections were included. The computed results when compared with the experimental ones show that, irrespective of the method used, the differences in the rotational barriers, ∆(E-TS) and ∆(Z-TS), are slight and below the 3 kcal mol-1 limit of the theoretical methods. In general the results using the PCM method were worse than the ones obtained from gas phase calculations or using the Onsager method, even though the PCM method is computationally most expensive. The calculations show, using either the Hartree-Fock or the B3LYP approach, that considering solvation using the Onsager method improves agreement with the experiment results. The calculated barrier heights, excluding the PCM method, agree broadly with the experimental results. Thus using the Onsager approach or gas phase calculations adequate results for barrier heights, but not for relative differences, were obtained.

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