Lithium orbital diagram

The orbital diagram—the kind you met in Chapter 4—represents the C-Li bond in methyl-lithium in terms of a sum of the atomic orbitals of carbon and lithium. Remember that, the more... 

We can now predict the electron configurations and orbital diagrams for the ground state of lithium, which has three electrons, and beryllium, which has four electrons ... 

As another example, consider the lithium atom (Z = 3) which has three electrons. The third electron cannot go into the 1 orbital because it would inevitably have the same four quantum numbers as one of the first two electrons. Therefore, this electron enters the next (energetically) higher orbital, which is the 2s orbital (see Figure 7.22). The electron configuration of lithium is Is ls, and its orbital diagram is... 

Since we could just as well have taken /i(l) = 2s(l)/3(l), the ground state of lithium is, like hydrogen, doubly degenerate, corresponding to the two possible orientations of the spin of the 2s electron. We might use the orbital diagrams... 

After helium, the next element in the periodic table is lithium, which has three electrons. Because of the restrictions imposed by the Pauli exclusion principle, an orbital can accommodate no more than two electrons. Thus, the third electron cannot reside in the Ij orbital. Instead, it must reside in the next available orbital with the lowest possible energy. According to Figure 6.23, this is the 2s orbital. Therefore, the electron configuration of lithium is l5 25 and the orbital diagram is... 

For the inner shells the outermost contour is again 0.025 Bohr 3/2. They are much steeper and, therefore, the increment is here 0.2 Bohr-3/2. Three of these inner shell contours are drawn. If the remaining inner shell contours were drawn, the inner part would be solid black. For this reason, the inner shell contours are not drawn beyond the third one and, instead, the value of the inner shell orbital at the position of the nucleus has been written into the diagram. From the figure, it is obvious that the inner shell of lithium is very similar in Li2 and LiH, and in a very practical sense transferable. However, note that the localized inner shell orbital of the lithium atom has a slight negative tail towards the other atom which yields a very small amount of antibinding. 

Note that all the superscripts for an atom must add up to the total number of electrons in the atom—1 for hydrogen, 3 for lithium, 11 for sodium, and so forth. Also note that the orbitals are not always listed in order of principal quantum number. The 4s orbital, for example, is lower in energy than the 3 dorbitals, as is indicated on the energy-level diagram of Figure 5-22. The 4s orbital, therefore, appears before the 3dorbitaI. 

A picture of the electron distribution in the frontier cr orbitals between carbon and lithium is revealed in the wire-mesh diagrams in Fig. 1.65, which show one contour of the acu and a cLi orbitals of methyllithium, unrealistically monomeric and in the gas phase. Comparing these with the schematic version in Fig. 1.64, we can see better how the s and px orbitals on lithium mix to boost the electron population between the nuclei in (jcLi, and to minimise it in [Pg.56]

Lithium (atomic number 3), 3Li, has three electrons to distribute among the subshells. Following the first arrow in the filling diagram, two electrons are added to the ls-orbital, filling it completely. The next higher arrow leads to the 2s-subshell. The third electron is placed in the 2s-orbital in the 2s-subshell. The configuration of lithium would be read as one-s-two, two-s-one. ... 

Orbital energy-level diagram for lithium metal. Occupied energy levels are indicated by blue lines and unoccupied energy levels by red lines. 

Figure 3.8 The two worksheets in the spreadsheet, fig3-8.xls, for the calculation of the orthonormal double-zeta Slater radial function of the lithium 2s orbital. The comparison graphs in this figure show the possible starting situation, with both C coefficients equal 1 and the C2 equal 0. In both cases, changing the value of cj in cell SCSI 1 leads to the best fit results shown in the next diagram.

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