The calculation of electronic properties of conjugated molecules is a problem of great interest in many areas of current research. We have developed a method based on using the static screened potential within the combined formalism of Green function theory and density response theory and apply this method to the calculation of electronic transition properties of a series of azabenzenes: pyridine, pyrazine, pyrimidine, pyridazine, s-triazine, as-triazine, and v-triazine. / This method consists of three basic stages of calculation. The first stage consists of a Pariser-Parr-Pople calculation using the Mataga-Nishimoto approximation for the potential. This produces a set of zero order molecular orbitals and energies which serve as input into the second stage of the method. The first step in this stage is the calculation of the free propagator from which, using techniques from diagrammatic perturbation theory, the dressed polarization propagator is obtained. This dressed propagator is calculated within the RPA with only diagonal exchange terms included and based on two different expansion: one is in terms of the singlet vertex function and the other in terms of the triplet vertex function. Using this we then calculate the static screened potential in three different ways. The first is based just on the free propagator while the other two are based on the two different dressed propagators calculated. Once these potentials are obtained we then return to stage 1 and re-iterate the PPP calculation using the static screened potentials in place of the Mataga-Nishimoto potential. This entire process is then repeated until the static screened potentials become self-consistent. From these self-consistent potentials molecular orbitals, energies, and generalized bond orders are obtained. These molecular orbitals and energies along with the self-consistent static screened potentials themselves serve as input into the equations of stage 3. It is here that transition energies and oscillator strengths are calculated according to either the RPA or the TDA and these final calculated quantities are compared as to their relative value depending on the type of approximations employed in order to make some qualitative assessment of their usefulness. / Source: Dissertation Abstracts International, Volume: 42-06, Section: B, page: 2424. / Thesis (Ph.D.)--The Florida State University, 1981.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_74544 |
| Contributors | DONALDSON, KURT DELMAS., Florida State University |
| Source Sets | Florida State University |
| Detected Language | English |
| Type | Text |
| Format | 192 p. |
| Rights | On campus use only. |
| Relation | Dissertation Abstracts International |
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