Back to Search
Start Over
Development of highly accurate approximate scheme for computing the charge transfer integral
- Source :
- The Journal of chemical physics. 143(7)
- Publication Year :
- 2015
-
Abstract
- The charge transfer integral is a key parameter required by various theoretical models to describe charge transport properties, e.g., in organic semiconductors. The accuracy of this important property depends on several factors, which include the level of electronic structure theory and internal simplifications of the applied formalism. The goal of this paper is to identify the performance of various approximate approaches of the latter category, while using the high level equation-of-motion coupled cluster theory for the electronic structure. The calculations have been performed on the ethylene dimer as one of the simplest model systems. By studying different spatial perturbations, it was shown that while both energy split in dimer and fragment charge difference methods are equivalent with the exact formulation for symmetrical displacements, they are less efficient when describing transfer integral along the asymmetric alteration coordinate. Since the “exact” scheme was found computationally expensive, we examine the possibility to obtain the asymmetric fluctuation of the transfer integral by a Taylor expansion along the coordinate space. By exploring the efficiency of this novel approach, we show that the Taylor expansion scheme represents an attractive alternative to the “exact” calculations due to a substantial reduction of computational costs, when a considerably large region of the potential energy surface is of interest. Moreover, we show that the Taylor expansion scheme, irrespective of the dimer symmetry, is very accurate for the entire range of geometry fluctuations that cover the space the molecule accesses at room temperature.
- Subjects :
- Physics
media_common.quotation_subject
General Physics and Astronomy
Equations of motion
Electronic structure
Potential energy
Asymmetry
symbols.namesake
Coupled cluster
Quantum mechanics
Potential energy surface
Taylor series
symbols
Statistical physics
Physical and Theoretical Chemistry
Coordinate space
media_common
Subjects
Details
- ISSN :
- 10897690
- Volume :
- 143
- Issue :
- 7
- Database :
- OpenAIRE
- Journal :
- The Journal of chemical physics
- Accession number :
- edsair.doi.dedup.....ba3a16e2cd85ee800b75a528e42f20ef