8th Liquid Matter Conference September 6-10, 2011 Wien, Austria ...

Tue 611:23-14:00P2.63A dynamical simulation study of the rotationalabsorption spectra of HCl diluted in liquid ArAntonio Padilla 1 and Justo Pérez 21 University of La Laguna, Avd Astrofisico Francisco Sanchez, sn, Facultad de Fisica38203, La Laguna, Spain2 University of La Laguna, La Laguna, SpainThe far-infrared absorption spectra of HCl diluted in liquid Ar has been calculated by means of amixed quantum-classical dynamical simulation. The diatomic rotation is treated by a quantum approachwhile the translational dynamics of the HCl-Ar liquid phase is treated classically by meansof molecular dynamics simulation. The calculations were realized at different thermodynamicstates of the liquid-vapor coexistence curve and compared with existing experimental data [1] inthe temperature range T=108-121 K. Three HCl-Ar potential models were checked, the HWK ofHolmgren et. al. [2], the LDMG of Laori et al. [3] and the M5 of Hutson et. al. [4]. The spectracalculated with the HWK potential shows a reasonable agreement with the experimental profile,although like in a previous study made with a stochastic approach [1], the theoretical rotationalresonances are more resolved than the experimental ones. The dominant isotropic part of the threeHCl-Ar potential models is quite similar among them, but the more weak anisotropic componentpresent significant differences that leads to a different rotational dynamics. For example, thespectra calculated with the LDMG potential are similar to the HWK ones at low frequency,although at high frequency the fine rotational structure is clearly more resolved for the first one.Additionally, important differences of the spectra calculted with the M5 potential with respectthe HWK and LDGM ones, can be observed in the low, mid and high frequency regions of therotational spectra.[1] A. Padilla, J. Pérez, W. A. Herrebout, B. J. Van der Veken and M. O. Bulanin, J. Mol.Struct. 976, 42 (2010).[2] S. L. Holmgren, M. Waldman and W. Klemperer, J. Chem. Phys. 67, 4414 (1977); 69, 1661(1978).[3] B. Laroi, O. Damak, O. Maillard and C. Girardet, J. Chem. Phys. 97, 2359 (1992).[4] J. M. Hutson and B. O. Howard, Mol. Phys. 45, 769 (1982).63