用耦合簇运动方程计算分子的多光子吸收截面

Multi-photon absorption cross sections calculated by coupled-cluster equation of motion method

简短评述了多光子吸收过程的原理与应用.由于该过程的高度非线性,对于分子的高激发态性质的描述要求很高,因为从本质上讲,这涉及到从低激发态到高激发态的跃迁过程.我们提出了用耦合簇运动方程方法并结合半经验哈密顿参数来计算大分子体系的多光子吸收截面.以蒽-卟啉-蒽分子为例,从激发态之间的跃迁密度分析发现,分子内电荷转移过程可以极大地增强三光子吸收.

In this work, we briefly introduce the studies on the experimental and theoretical progresses on the multi-photon absorption process in organic systems. Due to highly nonlinear characteristics, the precise descriptions for the higher excited states are highly demanded, because basically the electric dipole transitions from lower excited states to higher excited states are pertinent. We propose the coupled-cluster equation of motion method coupled with semiempirical Hamiltonian to calculate the multi-photon absorption cross-section for complex molecular systems. Taking anthracene-porphyrinanthracene triads as example, we found that the intra-molecular charge transfer process can largely enhance the three-photon absorption cross-section.