Barford William, Paiboonvorachat Nattapong
Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, United Kingdom.
J Chem Phys. 2008 Oct 28;129(16):164716. doi: 10.1063/1.3001584.
We introduce a mapping from configuration interaction singles wavefunctions, expressed as linear combinations of particle-hole excitations between Hartree-Fock molecular orbitals, to real-space exciton wavefunctions, expressed as linear combinations of particle-hole excitations between localized Wannier functions. The exciton wavefunction is a two-dimensional amplitude for the exciton center-of-mass coordinate, R, and the electron-hole separation (or relative coordinate), r, having an exact analogy to one-dimensional hydrogenlike wavefunctions. We describe the excitons by their appropriate quantum numbers, namely, the principle quantum number, n, associated with r and the center-of-mass pseudomomentum quantum number, j, associated with R. In addition, for models with particle-hole symmetry, such as the Pariser-Parr-Pople model, we emphasize the connection between particle-hole symmetry and particle-hole parity. The method is applied to the study of excitons in trans-polyacetylene and poly(para-phenylene).
我们引入一种映射，从以Hartree-Fock分子轨道间粒子-空穴激发的线性组合表示的组态相互作用单重态波函数，到以局域化Wannier函数间粒子-空穴激发的线性组合表示的实空间激子波函数。激子波函数是激子质心坐标R和电子-空穴间距（或相对坐标）r的二维振幅，与一维类氢波函数有确切的类比关系。我们用适当的量子数来描述激子，即与r相关的主量子数n和与R相关的质心赝动量量子数j。此外，对于具有粒子-空穴对称性的模型，如巴黎-帕尔-波普尔模型，我们强调粒子-空穴对称性与粒子-空穴宇称之间的联系。该方法应用于反式聚乙炔和聚对亚苯基中激子的研究。
