Electron index order

Some people prefer this form because it places the two mutually repelling charge clouds on the two sides of the operator. It is important to realize that the parenthetical expression (/ / jj) and the bra-ket shorthand ij i j) correspond to different conventions for electron index order, and are really the same integral. Returning to Eq. (A7-21), we see that it is equal to... 

The two-electron integrals involve the LCAO orbitals, and the time-consuming part of a traditional Cl calculation is the transformation of these to integrals involving the basis functions. This is often referred to as the four-index transformation. Not only that, it turns out that traditional Cl calculations are very slowly convergent we have to add a vast number of excited states in order to improve the energy significantly. 

Information on the electronic configuration of each nonhydrogen atom is incorporated in the second order atomic index (S ) of the atom. 

Since the first structure determination by Wadsley [56] in 1952 there has been confusion about the correct cell dimensions and symmetry of natural as well of synthetic lithiophorite. Wadsley determined a monoclinic cell (for details see Table 3) with a disordered distribution of the lithium and aluminium atoms at their respective sites. Giovanoli et al. [75] found, in a sample of synthetic lithiophorite, that the unique monoclinic b-axis of Wadsley s cell setting has to tripled for correct indexing of the electron diffraction patterns. Additionally, they concluded that the lithium and aluminum atoms occupy different sites and show an ordered arrangement within the layers. Thus, the resulting formula given by Giovanelli et al. 

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