guest ::
| Home > Publications database > Alignment and mixed-field orientation of complex molecules |
| Home > Publications database > Alignment and mixed-field orientation of complex molecules |
| Conference Presentation (Invited) | PUBDB-2018-05654 |
; ; ; ;
2018
Abstract: Investigating the structure and dynamics of molecules is the goal of many theoretical and experimental studies. Fixing molecules in space facilitates and improves a variety of experimental techniques such as x-ray or electron diffraction, photoelectron imaging and high-harmonic generation. Techniques used to fix molecules in space include adiabatic and impulsive alignment and mixed-field orientation. Strong degrees of alignment and orientation have been achieved for different symmetric and asymmetric top molecules using these methods. For many molecular systems, the rigid rotor approximation provides a good description of the degree of alignment and orientation. However, it is a priori not clear how, in general, large amplitude internal motions, such as internal rotations, modify the overall rotational dynamics. For special cases of highly symmetric, e.g., G$_{16}$, molecules, the torsion-rotation coupling was observed [1,2]. However, more generic solute-solvent clusters with unsymmetric structures and light and fast internal rotors have not been treated.Here, we theoretically investigate the impact of the coupling of the rotational angular momentum and internal rotation or nuclear spins on the alignment and mixed-field orientation of different molecular systems. We analyze the adiabatic alignment and mixed-field orientation of the prototypical indole(H$_2$O) cluster [3,4] where the water molecule undergoes and internal rotation. Our results for the rotational and torsional dynamics show that the coupling of the internal and overall rotation is small and that indole(H$_2$O) can be treated as a rigid molecule for typical laser field strengths used in experiments. In addition, we explore the parameter space for which this approximation holds and when the field-free and field-induced coupling of the two motions can no longer be neglected.A similar discussion is in order for other angular momenta, such as electronic or nuclear spins [5,6]. Thus, we also explore the role played by the hyperfine quadrupole coupling in the laser alignment dynamics of iodobenzene.References:[1] C. B. Madsen, L. B. Madsen, S. S. Viftrup, M. P. Johansson, T. B. Poulsen, L. Holmegaard, V. Kumarappan, K. A. Jørgensen, and H. Stapelfeldt , Phys. Rev. Lett. 102, 073007 (2009)[2] T. Grohmann, M. Leibscher, and T. Seideman, Phys. Rev. Lett. 118, 203201 (2017)[3] Y.-P. Chang, D. A. Horke, S. Trippel, and J. Küpper, Int. Rev. Phys. Chem. 34, 557 (2015)[4] S. Trippel, J. Wiese, T. Mullins, and J. Küpper, J. Chem. Phys., 148, 101103 (2018)[5] E. F. Thomas, A. A. Søndergaard, B. Shepperson, N. E. Henriksen, and H. Stapelfeldt, Phys. Rev. Lett. 120, 163202 (2018)[6] K. Grygoryeva, J. Rakovský, O. Votava, and M. Fárník, J. Chem. Phys., 147 013901 (2017)
|
The record appears in these collections: |
