The dipole-dipole dispersion forces between spherical atoms from the Callen-Welton linear response theory
✍ Scribed by M. Battezzati
- Publisher
- Elsevier Science
- Year
- 1984
- Tongue
- English
- Weight
- 823 KB
- Volume
- 125
- Category
- Article
- ISSN
- 0378-4371
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✦ Synopsis
The dispersion interaction energy between spherical atoms is derived on the basis of linear response theory, by evaluation of the cross terms of the response to a long-wavelength electric field applied to each other atom, in the spirit of the Lifshitz theory. Then the correlation energy of the corresponding fluctuations is evaluated by application of the Hellmann-Feynman theorem. The self-consistency is easily introduced in this scheme, leading to a general expression of the interaction energy in terms of the poles of the linear response function of the whole system, related to those of the separated constituents. This is shown to be approximately equivalent to the variation of the zero-point energy of each independent oscillator, according to a generalization of London's formula for oscillating dipoles.