Where Are the Electrons

Where are the electrons . This question too can only be studied experimentally for molecules in equilibrium and in a roughly homogeneous environment such as a crystal or in solution. What we really want to know is how the distribution of these electrons around the nuclei determine the likelihood of effective collision and how they then behave during the interaction. Since molecules interact most strongly at their accessible surfaces/ it is important to know what these surfaces look like. 

Ultimately, the treatment of electronic structure in extended systems is no more complicated (nor is it less so) than in discrete molecules. The bridge to local chemical action advocated here is through decompositions of the DOS and the crystal orbital overlap population (COOP) curves. These deal with the fundamental questions Where are the electrons Where can I find the bonds ... 

Solution of the Schrodinger equation provides two main pieces of information the total electronic energy of the system (the repulsion energy between motionless nuclei can be simply calculated by a Coulomb sum), and the wavefunction F(x, y, z, t), which in turn gives the electron density g(x,y,z) and a formal answer to the question where are the electrons , because the quantity ... 

Electrons in a bonding molecular orbitals are most likely to be found in the region between the two bonded atoms. Why does this arrangement favor bonding In a o- antibonding orbital, where are the electrons most likely to be found in relation to the nuclei in a bond ... 

Where are the electrons We ha ve six electrons per monomer to distribute, and these are used to fill bands 1-3. Bands 4-6 are empty. Band 3, therefore, is the valence band because it contains the highest occupied crystal orbital, and band 4 is the conduction band. The Fermi level Ep lies at the zone center in this system, while it is at the zone edge for polyacetylene. There is no real-world significance to this distinction. One very meaningful distinction between polyacetylene and PPP, however, is evident at HMO level. By inspection you can see that the highest occupied and lowest unoccupied crystals orbitals should not be degenerate in the case of PPP. PPP has a finite band gap in HMO theory, while polyacetylene does not. 

Holland PL. Metal-dioxygen and metal-dinitrogen complexes where are the electrons Dalton Trans. 2010 39 5415-5425. 

The wavefunction allows a calculation of the molecular electron density p(x,y,z). In a way, this is the answer to the question where are the electrons . The electrostatic potential generated by the molecule can be calculated from the density, and this is useful in predicting what a molecule will do when it comes into close contact with another molecule the electrostatic potential is at the origin of control of mutual recognition in molecular complexes and condensed phases, as well as of some directional aspects of reactivity (Section 4.2). 

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