The thermal-average effect on the field-free orientation of the NaI molecule with full-dimensional random-phase wavefunctions

• Published in: Chemical physics letters Vol. 783; p. 139052
• Main Authors: Hu, Jin-Wei, Han, Yong-Chang
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 16.11.2021
• Subjects: Full-dimensional random-phase wavefunctions; Orientation; Thermal-average; Orientation; Full-dimensional random-phase wavefunctions; Thermal-average
• ISSN: 0009-2614; 1873-4448
• DOI: 10.1016/j.cplett.2021.139052

Graphical Abstract [Display omitted] •NaI orientation up to 1000 K is simulated by full-dimensional dynamics.•A distinguishable periodic field-free orientation is observed at 1000 K.•|〈cosθ〉|max remains at ω0=0.15 THz with the increase in temperature. The influence of the thermal average of initial rovibrational states on the orientation of the NaI molecule induced by a single-cycle terahertz pulse is investigated using the random-phase wavefunctions method. |〈cosθ〉|max as a function of the laser central frequency ω0 is obtained at different temperatures. Firstly, although the orientation is suppressed at high temperatures, a distinguishable periodic field-free orientation is still observable at T=1000 K. Secondly, the variation of |〈cosθ〉|max with ω0 is strongly dependent on the temperature. We ascribe this variation to different thermal distributions of the initial rovibrational states and to the consequently different final rotational distributions.