LSDA method

The LSDA approximation in general underestimates the exchange energy by 10%, thereby creating errors which are larger tlian the whole correlation energy. Electron correlation is furthermore overestimated, often by a factor close to 2, and bond strengths are as a consequence overestimated. Despite the simplicity of the fundamental assumptions, LSDA methods are often found to provide results with an accuracy similar to that obtained by wave mechanics HE methods. 

Should DFT methods be considered ab initio or semi-empirical If ab initio is taken to mean the absence of fitting parameters, LSDA methods are ab initio, but gradient... 

The earliest class of DFT methods is known as local (electron) density approximation (LDA) methods in the case that the total electron density is decomposed into individual spin densities for +1 /2 and -1/2 spin we refer to these methods as local spin density approximation (LSDA) methods. In these methods the total molecular XC energy is evaluated by integration on a numerical grid of the electron density, and the energy is a function of only the specific value of the density at each point, hence the local density ... 

One of the most commonly used LSDA methods combines the exchange potential of Slater [6] and the correlation potential of Vosko et al. [7], and is referred to as the SVWN DFT method. 

The outline of the present chapter is as follows. Section 2 deals with the relevant physical, electronic, and magnetic properties of the lanthanides. Section 3 reviews briefly the above-mentioned theoretical methods, with the focus on the SIC-LSDA method, and, in particular, the full implementation of SIC, involving repeated transformations between Bloch and Wannier representations (Temmerman et al., 1998). This is then compared with the local-SIC, implemented in the multiple scattering theory (Liiders et al., 2005). Section 4 deals with the valence (Strange et al., 1999) and valence transitions of the lanthanides. Section 5 discusses the local magnetic moments of the lanthanides. Section 6 discusses two spectroscopies applied to lanthanides and some of their compoimds. Section 7 outlines a methodology of calculating the finite temperature (T) properties of the lanthanides and their... 

---