Vosko-Wilk-Nusair correlation

VWN5 A Vosko, Wilk, Nusair correlation functional... 

We have used the basis set of the Linear-Muffin-Tin-Orbital (LMTO) method in the atomic sphere approximation (ASA). The LMTO-ASA is based on the work of Andersen and co-workers and the combined technique allows us to treat all phases on equal footing. To treat itinerant magnetism we have employed the Vosko-Wilk-Nusair parametrization for the exchange-correlation energy density and potential. In conjunction with this we have treated the alloying effects for random and partially ordered phases with a multisublattice generalization of the coherent potential approximation (CPA). 

The LDA exchange-correlation potential used in this study was not the common Vosko, Wilk, Nusair parameterization of the Ceperley-Adler data for the uniform electron gas but the potential of Heidin and Lundqvist.68... 

VWN(Vosko, Wilk, Nusair)(12) p / +correl. PZ(Perdew, Zunger) (1J) electron gas exchange and correlation from accurate Quantum Monte Carlo calcs, of Ceperley and Alder (14)... 

Hedin- Lundqvist, HL, exchange-correlation potential [37], which is equivalent to our earlier use [130] of the von Barth-Hedin potential, vBH, [38] with parameter values as used by Hedin and Lundqvist. Calculations were also performed using the Xa form, with a = 0.7 [4] and the Vosko-Wilk-Nusair form of Vxc [41]. A somewhat lower total energy was obtained by inclusion of the 3d, and in particular the 3p and 3d, basis functions, compared with the results obtained using the minimal basis set. 

To confirm the minimum point of the total energy profile with respect to the U=0 distance, other exchange - correlation potentials were also examined a local density functional by Vosko-Wilk-Nusair (VWN) (14) and a nonlocal... 

The one-electron Kohn-Sham equations were solved using the Vosko-Wilk-Nusair (VWN) functional [27] to obtain the local potential. Gradient correlations for the exchange (Becke fimctional) [28] and correlation (Perdew functional) [29] energy terms were included self-consistently. ADF represents molecular orbitals as linear combinations of Slater-type atomic orbitals. The double- basis set was employed and all calculations were spin unrestricted. Integration accuracies of 10 -10 and 10 were used during the single-point and vibrational frequency calculations, respectively. The cluster size chosen for Ag or any bimetallic was... 

GGA functionals. Slater (S) exchange [68] and Vosko-Wilk-Nusair (VWN) correlation [74] LDA functionals, and the HF exchange integral with three parameters ... 

VOSKO-WILK-NUSAIR EXCHANGE CORRELATION CAN. J. PHYS. 58,1200(1980)... 

Theoretical work on the oxidation reactions of aromatic hydrocarbons is scarce. Bartolotti and Edney [10] used a simple density functional approach with the local exchange correlation functional developed by Vosko-Wilk-Nusair [11] to identify potential intermediates produced in the OH addition initiated atmospheric photooxidation of toluene. Although their energy results were acknowledgely preliminary in nature, their calculations were able to confirm certain aspects of the proposed reaction mechanism [2,3] and to predict the importance of carbonyl compounds containing... 

Any exchange functional can be combined with any correlation functional. For example, the notation BLYP/6-31G denotes a DF calculation done with the Becke 1988 exchange functional and the Lee-Yang-Parr correlation functional, with the KS orbitals expanded in a 6-31G basis set. The letter S (which acknowledges Slater s Xa method) denotes the LSDA exchange functional (15.140). VWN denotes the Vosko-Wilk-Nusair expression for the LSDA correlation functional (actually, these workers gave two differ-... 

Kafafi devised the hybrid K2-BVWN (standing for Kafafi 2-parameter, Becke, Vosko-Wilk-Nusair) exchange-correlation functional [S. A. Kafafi, /. Phys. Chem. A, 102,10404 (1998)]. K2-BVWN/6-311+G(2df) calculations of of 350 species had... 

The Xa method is an example of LDA in which the correlation energy is neglected and the exchange energy expression is multiplied by a parameter a. A fairly accurate expression for the correlation energy of the uniform electron gas, the VWN (Vosko, Wilk, Nusair) functional, was derived by fitting it to Monte Carlo results. 

From Reference 13, triple-J + polarization basis set for heavy atoms, double- + polarization basis set for hydrogen atoms. Vosko-Wilk-Nusair LSDA XC functional. Gradient-corrected Perdew— ng exchange and Perdew correlation functionals. 

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