Configuration molecular electron

For practical implementations it is necessary to represent the molecular electronic wave functions as a linear combination of some convenient set of basis functions. In principle any choice of basis set is permissible although the basis set must span any electronic configuration of the molecule. This implies that the basis must form a complete set. 

Some of these approximate forms of wave function possess a character of particular theoretical interest. One such is the "uni-configurational wave function. This implies an appropriate linear combination of antisymmetrized products of molecular spin orbitals in which all antisymmetrized products belong to the same "electron configuration . The electron configuration of an antisymmetrized product is defined as the set of N spatial parts appearing in the product of spin orbitals. For instance, a uni-configurational wave function with N = 2, S = 0, Ms=0 is expressed as... 

We are therefore led to make the one-configuration separate electron group model for molecular electronic structure. We write... 

The energy state, electronic configuration, molecular state symmetry and the nature of transition in formaldehyde molecule... 

Energy state Electronic configuration Molecular state symmetry Selection rule for polarization of transition dipole... 

Collier, C. P., Wong, E. W., Belohradsky, M., etal., Electronically configurable molecular-based logic gates. Science 1999, 285,391-394. 

This remarkable molecular memory was preceded by two other related examples of addressable molecular electronics from the Stoddart and Heath groups in collaboration with Hewlett-Packard scientists. First in 1999 a [2] rotaxane based system was configured into molecular AND and OR logic gates,63 then in 2000 a [2] catenane based molecular switch was reported.64 The molecular basis for the operation of this switch is the same as in 11.67, namely reorientation in response to reduction of... 

Fig. 4a Preferred configuration of electron spins in the a orbital connecting a hydrogen atom to an sp2-hybridized carbon atom bearing unpaired 7t spin density, b Molecular n orbital consisting of two carbon pz orbitals and an H2 group orbital generated by hyperconjugative interaction of an, fp2-hybridized C atom bearing unpaired spin with a CH2—R group...

Fig. 1. Schematic plot of a molecular electronic device in the Metal-Molecule-Metal configuration. The device consists of a scattering region connected to external sources through metallic leads. The scattering region (the extended molecule) contains the molecule and several layers of the metal leads. The molecule is placed between lines...

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