First-principles molecular-dynamics simulation of biphenyl under strong laser pulses by time-dependent density-functional theory

作者：Haruyama Jun^*; Hu Chunping; Watanabe Kazuyuki

来源：Physical Review A, 2012, 85(6): 062511.

DOI：10.1103/PhysRevA.85.062511

The femtosecond laser reaction dynamics of the 3,5-difluoro-3%26apos;,5%26apos;-dibromo-biphenyl (DFDBrBPh) molecule is investigated using time-dependent density-functional theory combined with molecular-dynamics (TDDFT-MD) simulation. This work is based on a recent experiment that monitored torsional motion of the DFDBrBPh molecule by femtosecond time-resolved Coulomb explosion imaging [Madsen et al., Phys. Rev. Lett. 102, 073007 (2009)]. The results confirm that the probe pulse triggers a Coulomb explosion and the kick pulse induces the torsional motion of two phenyl rings, using the experimental settings of the lasers. The Coulomb explosion dynamics simulation verifies that the F and Br atoms dissociate to the ion detector while maintaining their initial alignment with respect to the phenyl rings, which is the fundamental basis of Coulomb explosion imaging of molecular torsion. Furthermore, the period and amplitude of the torsional motion obtained by the simulation are consistent with the experimental values. This validates the ability of the TDDFT-MD method to reveal the underlying mechanism of experimentally observed molecular torsional dynamics.

• 出版日期2012-6-21