Vosko, Wilk, Nusair

We have used the multisublattice generalization of the coherent potential approximation (CPA) in conjunction with the Linear-MufRn-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 for the local spin density approximation (LSDA) the Vosko-Wilk-Nusair parameterization". 

SVWN Model. (Slater, Vosko, Wilk, Nusair) A Density Functional Model which involves the Local Density Approximation. 

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

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... 

Figure 2-6. Comparison of calculated and experimental vertical excitation energies of Be and H20. TDDFT is based on the Slater-Vosko-Wilk-Nusair functional. See Ref. [110] for details...

The extension of TDDFT and Tamm-Dancoff TDDFT to crystalline polymers is straightforward within the formalisms of Section 2.2.2. Figure 2-7 summarizes the results of TDDFT calculations of the photoconduction, photoemission, and optical absorption thresholds (energy gap, ionization energy, and excitation energy) of polyethylene as a function of basis set [50], The Slater-Vosko-Wilk-Nusair functional [116, 117] is used, but the following conclusion is unaltered... 

Figure 2-7. TDDFT (the Slater-Vosko-Wilk-Nusair functional) predictions of the photoconduction (fundamental gap), photoemission (ionization), and optical absorption (excitation) energies of polyethylene [50]...

Figure 2-8. Convergence of the excitation energy to the lowest-lying singlet exciton computed by CIS and TDDFT using the Slater-Vosko-Wilk-Nusair functional with the STO-3G basis set as a function of the number of wave vector sampling points (K) [50]. The error is defined as the absolute difference from the K = 100 results. The converged (K = 100) result with TDDFT is very close to the fundamental energy gap...

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... 

Here j SDA timkind of accurate pure DFT LSDA non-gradient-corrected exchange functional alluded to in section 7.2.3.4b, is the KS-orbital-based HF exchange energy functional of Eq. (7.30), is the Becke 88 exchange functional mentioned above, is the Vosko, Wilk, Nusair function (VWN, or Slater VWN, SVWN... 

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)... 

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