Structural and dynamic properties of SPC/E water

• Main Author: M. G. Campo
• Format: Article
• Language: English
• Published: Papers in Physics 2010-02-01
• Series: Papers in Physics
• Subjects: SPC/E water; hydrogen bonds; q-exponential; water structure; water dynamics
• Online Access: http://www.papersinphysics.org/index.php/papersinphysics/article/view/10/pdf10

<p>I have investigated the structural and dynamic properties of water by performing a series of molecular dynamic simulations in the range of temperatures from 213 K to 360 K, using the Simple Point Charge-Extended (SPC/E) model. I performed isobaric-isothermal simulations (1 bar) of 1185 water molecules&nbsp; using the GROMACS package. I quantified the structural properties using the oxygen-oxygen radial distribution functions, order parameters, and the hydrogen bond distribution functions, whereas, to analyze the dynamic properties I studied the behavior of the history-dependent bond correlation functions and the non-Gaussian parameter $alpha_{2}(t)$ of the mean square displacement of water molecules. When the temperature decreases, the translational ($au$) and orientational ($Q$) order parameters are linearly correlated, and both increase indicating an increasing structural order in the systems. The probability of occurrence of four hydrogen bonds and $Q$ both have a reciprocal dependence with $T$, though the analysis of the hydrogen bond distributions permits to describe the changes in the dynamics and structure of water more reliably. Thus, an increase on the <em>caging</em> effect and the occurrence of long-time hydrogen bonds occur below $sim$ 293 K, in the range of temperatures in which predominates a four hydrogen bond structure in the system.</p><p><strong>Received:</strong> 13 July 2009, <strong>Revised:</strong> 29 December 2009, <strong>Accepted:</strong> 7 February 2010; <strong>Edited by:</strong> S. A. Cannas; <strong>Reviewed by:</strong> P. Netz, Inst. de Qu&iacute;mica, Univ. Federal do Rio Grande do Sul, Brazil; <strong>DOI:</strong> 10.4279/PIP.020001</p>