Centrifugal effects atoms

As a molecule rotates faster, the bond between the two atoms stretches this centrifugal effect increases the moment of inertia so that there is a reduction in the rotational constant which increases with increasing J. This effect can be described by the addition of an extra term to the effective Hamiltonian for the rotational kinetic energy ... 

Equilibria. As a worked out example, I wish to present here the dynamics and relative TS associated with a very well known system of molecular physics, the van der Waals molecule. Simply stated, a van der Waals molecule AB is bound not by the creation of electronic orbitals extending over both fragments A and B but rather by the attraction due to multipolar electric forces between the two fragments A and B. In addition to this attraction, there also exists a chemical repulsion, responsible for the nonreactivity of A and B. Since the bonding is multipolar, it is weak, of the order of tens to hundreds cm (1 atomic unit of energy 2.19 x 10 cm ). Because the bonding is so weak, it is to be expected that centrifugal effects will be important, as has often been experimentally and theoretically observed. 

Since the centrifugal term is present in the radial Schrodinger equation for all atoms, we must explain why centrifugal effects only dominate the inner valence spectra of fairly heavy atoms. Centrifugal barrier effects are present even in H. However, they act differently in transition elements or lanthanides. 

Fig. 12a-c. Schematic representation of the effective potential Vejf and of different possibilities of localized and itinerant states for electrons of high 1 quantum number, a) The solid line d represents the periodic potential set-up by the cores R and R +i, which is a superimposition of central potential a dashed line). The dashed line b represents the centrifugal potential of kinetic origin 1(1 + l)/2 R in an atom, and c dashed line) the effective potential V f for an atom (compare Fig. 6) and full line) for a solid, b) Relative to two shapes of the effective potential Ve, two examples of localized state are given 1. resonant state 2. fully localized state. Notice that 1. is very near to Ep. h and t represent hopping and tunneling processes, c) A narrow band is formed (resonance band), pinning Ep 3. narrow band... 

When the atoms are approached, to form a lattice (as in a metal), the effective potential Vett is now the combination of the centrifugal term and the periodic potential V(. Troughs and barriers are created in the inter-core zone (see Fig. 12a, full lines). 

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