The influences of the initial states of HCl on the stereodynamics properties of the Ca+HCl reaction are investigated by utilizing the method based on the quasi-classical trajectory (QCT) theory and the analytical potential energy surface (APES). The orientation and alignment behaviors for the rotational angular momentum of the product, along with the generalized differential cross-section (PDDCS) dependent polarization, are employed to explore the stereodynamics properties. The initial rotational states of the HCl molecule impose a remarkable affection on the vector correlation distributions, regardless of the orientation, alignment, or PDDCS. The obvious forward or backward scattering, as well as the weak sideway scattering phenomena, are found for the different initial rotational states of the HCl molecule. The initial higher rotational-excited state of j=3 results in more obvious stereodynamics effects.

The effects of HCl rotational excited states on the stereodynamics of the Ca+HCl reaction are explored based on quasi-classical trajectory (QCT) theory with potential energy surface (PES) [Verbockhave et al., J. Chem. Phys. 2005,122,204307]. Vibrational level v=0 and rotational level j=0-3 are considered. The polarization-dependent generalized differential cross sections (PDDCSs) and alignments of the product rotational angular momentum are used to demonstrate the stereodynamics effects. The rotational quantum number has a considerable influence on the distribution of vector correlation, including alignment, orientation, and PDDCSs. The product molecules are strongly forward and backward scattering and weakly sideway scattering because the reactant molecule HCl is in the rotational ground state and the lower rotational excited states. Strongly forward scattering is observed while the reactant is in high rotational excited states.