Local density approximation LDA

LCAO (linear combination of atomic orbitals) refers to construction of a wave function from atomic basis functions LDA (local density approximation) approximation used in some of the more approximate DFT methods... 

Aside from the well-known LDA (local density approximation (26, 27) BLYP (Becke-Lee-Yang-Parr (28, 29)) and B3LYP (29, 30) functionals, we considered the more recent B97-1 functional (which is a reparametrization (31) of Becke s 1997 hybrid functional), the B97-2 functional (32) (a variation of B97-1 which includes a kinetic energy density term), and the HCTH-407 (33) functional of Boese and Handy (arguably the best GGA functional in existence at the time of writing). The rationale behind the Wlc (Weizmann-1 cheap) approach is extensively discussed elsewhere. (34,35) For the sake of self-containedness of the paper, we briefly summarize the steps involved for the specific system discussed here ... 

LDA local density approximation GGA generalized gradient approximation Trom [92]... 

Helgaker et alP presented a fully analytical implementation of spin-spin coupling constants at the DFT level. They used the standard procedure for linear response theory to evaluate second-order properties of PSO, FC and SD mechanisms. Their calculation involves all four contributions of the nonrelativistic Ramsey theory. They tested three different XC functionals -LDA (local density approximation), BLYP (Becke-Lee-Yang-Parr), " and B3LYP (hybrid BLYP). All three levels of theory represent a... 

For an inhomogeneous system of interacting electrons the functional Exc[n+,n ] is unknown. In this method the spin-polarized generalization LSD (Local Spin Density) version of LDA (Local Density Approximation) approximation is used. n(r) is supposed to vary slowly and the energy can be expressed as... 

LCGTO linear combination of Gaussian-type orbitals LDA local density approximation... 

LDA Local Density Approximation A density functional theory (DFT) method... 

---