Optical Kerr effect in supercooled water.
We present molecular dynamics simulations of the optical Kerr effect in liquid and supercooled water and compare with recent time-resolved Kerr spectroscopy measurements [R. Torre, Nature (London) 428, 296 (2004)]. The short time features of the Kerr response, characterized by peaks near 15, 60, and 160 fs, are weakly temperature dependent. The long-time decay is well described by a stretched exponential with a nearly constant stretch parameter and relaxation times that follow a power law approximately (T-T(S))(-gamma), with T(S)=198.3 K and gamma=2.35. Our findings are discussed in the light of the spectroscopy data and previous simulation analyzes of the structural relaxation in supercooled water.
Skaf
Munir S
MS
Institute of Chemistry, State University of Campinas, Cedex P. 6154, Campinas-SP, 13084-971, Brazil. skaf@iqm.unicamp.br
Sonoda
Milton T
MT