Computational probes of molecular motion in the Lewis-Wahnström model for ortho-terphenyl

@article{lombardo06, abstract = {We use molecular dynamics simulations to investigate translational and rotational diffusion in a rigid three-site model of the fragile glass former ortho-terphenyl, at 260 KT346 K and ambient pressure. An Einstein formulation of rotational motion is presented, which supplements the commonly used Debye model. The latter is shown to break down at supercooled temperatures as the mechanism of molecular reorientation changes from small random steps to large infrequent orientational jumps. We find that the model system exhibits non-Gaussian behavior in translational and rotational motion, which strengthens upon supercooling. Examination of particle mobility reveals spatially heterogeneous dynamics in translation and rotation, with a strong spatial correlation between translationally and rotationally mobile particles. Application of the Einstein formalism to the analysis of translation-rotation decoupling results in a trend opposite to that seen in conventional approaches based on the Debye formalism, namely, an enhancement in the effective rate of rotational motion relative to translation upon supercooling. {\copyright}2006 American Institute of Physics}, author = {Lombardo, Thomas G. and Debenedetti, Pablo G. and Stillinger, Frank H. }, citeulike-article-id = {1298182}, doi = {10.1063/1.2371111}, journal = {The Journal of Chemical Physics}, keywords = {cages, diffusion, otp, rotation, simulation}, number = {17}, pages = {174507}, posted-at = {2007-11-25 18:46:33}, priority = {5}, publisher = {AIP}, title = {Computational probes of molecular motion in the Lewis-Wahnstr\"{o}m model for ortho-terphenyl}, url = {http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal\&id=JCPSA6000125000017174507000001\&idtype=cvips\&gifs=yes}, volume = {125}, year = {2006} }

TY - JOUR ID - lombardo06 L3 - citeulike-article-id:1298182 TI - Computational probes of molecular motion in the Lewis-Wahnström model for ortho-terphenyl JF - The Journal of Chemical Physics VL - 125 IS - 17 SP - 174507 EP - 174507 PB - AIP N2 - We use molecular dynamics simulations to investigate translational and rotational diffusion in a rigid three-site model of the fragile glass former ortho-terphenyl, at 260 KT346 K and ambient pressure. An Einstein formulation of rotational motion is presented, which supplements the commonly used Debye model. The latter is shown to break down at supercooled temperatures as the mechanism of molecular reorientation changes from small random steps to large infrequent orientational jumps. We find that the model system exhibits non-Gaussian behavior in translational and rotational motion, which strengthens upon supercooling. Examination of particle mobility reveals spatially heterogeneous dynamics in translation and rotation, with a strong spatial correlation between translationally and rotationally mobile particles. Application of the Einstein formalism to the analysis of translation-rotation decoupling results in a trend opposite to that seen in conventional approaches based on the Debye formalism, namely, an enhancement in the effective rate of rotational motion relative to translation upon supercooling. ©2006 American Institute of Physics KW - cages KW - diffusion KW - otp KW - rotation KW - simulation AU - Lombardo, Thomas AU - Debenedetti, Pablo AU - Stillinger, Frank PY - 2006/// UR - http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JCPSA6000125000017174507000001&idtype=cvips&gifs=yes ER -