On-the-fly ab initio three thawed Gaussians approximation: A semiclassical approach to Herzberg-Teller spectra

التفاصيل البيبلوغرافية
العنوان: On-the-fly ab initio three thawed Gaussians approximation: A semiclassical approach to Herzberg-Teller spectra
المؤلفون: Begušić, Tomislav, Patoz, Aurélien, Šulc, Miroslav, Vaníček, Jiří
المصدر: Chem. Phys., 515, 152 (2018)
سنة النشر: 2019
المجموعة: Physics (Other)
Quantum Physics
مصطلحات موضوعية: Physics - Chemical Physics, Physics - Computational Physics, Quantum Physics
الوصف: Evaluation of symmetry-forbidden or weakly-allowed vibronic spectra requires treating the transition dipole moment beyond the Condon approximation. To include vibronic spectral features not captured in the global harmonic models, we have recently implemented an on-the-fly ab initio extended thawed Gaussian approximation, where the propagated wavepacket is a Gaussian multiplied by a linear polynomial. To include more anharmonic effects, here we represent the initial wavepacket by a superposition of three independent Gaussian wavepackets - one for the Condon term and two displaced Gaussians for the Herzberg-Teller part. Application of this ab initio "three thawed Gaussians approximation" to vibrationally resolved electronic spectra of the phenyl radical and benzene shows a clear improvement over the global harmonic and Condon approximations. The orientational averaging of spectra, the relation between the gradient of the transition dipole moment and nonadiabatic coupling vectors, and the details of the extended and three thawed Gaussians approximation are discussed.
Comment: Final form available via open access in Chem. Phys. at https://www.sciencedirect.com/science/article/pii/S0301010418306220
نوع الوثيقة: Working Paper
DOI: 10.1016/j.chemphys.2018.08.003
URL الوصول: http://arxiv.org/abs/1901.05208
رقم الأكسشن: edsarx.1901.05208
قاعدة البيانات: arXiv