45 |
|
known low-pressure ice structures under all of these water models. |
46 |
|
Additionally, potential truncation was shown to have an effect on the |
47 |
|
calculated free energies, and can result in altered free energy |
48 |
< |
landscapes. Structure factor for the new crystal were generated and |
49 |
< |
we await experimental confirmation of the existence of this new |
50 |
< |
polymorph. |
48 |
> |
landscapes. Structure factor predictions for the new crystal were |
49 |
> |
generated and we await experimental confirmation of the existence of |
50 |
> |
this new polymorph. |
51 |
|
\end{abstract} |
52 |
|
|
53 |
|
%\narrowtext |
105 |
|
|
106 |
|
\begin{figure} |
107 |
|
\includegraphics[width=\linewidth]{unitCell.eps} |
108 |
< |
\caption{Unit cells for (A) Ice-{\it i} and (B) Ice-$i^\prime$, the |
109 |
< |
elongated variant of Ice-{\it i}. The spheres represent the |
108 |
> |
\caption{Unit cells for (A) Ice-{\it i} and (B) Ice-{\it i}$^\prime$, |
109 |
> |
the elongated variant of Ice-{\it i}. The spheres represent the |
110 |
|
center-of-mass locations of the water molecules. The $a$ to $c$ |
111 |
|
ratios for Ice-{\it i} and Ice-{\it i}$^\prime$ are given by |
112 |
|
$a:2.1214c$ and $a:1.7850c$ respectively.} |
138 |
|
from which Ice-{\it i} was crystallized (SSD/E) in addition to several |
139 |
|
common water models (TIP3P, TIP4P, TIP5P, and SPC/E) and a reaction |
140 |
|
field parametrized single point dipole water model (SSD/RF). It should |
141 |
< |
be noted that a second version of Ice-{\it i} (Ice-$i^\prime$) was |
142 |
< |
used in calculations involving SPC/E, TIP4P, and TIP5P. The unit cell |
143 |
< |
of this crystal (Fig. \ref{iceiCell}B) is similar to the Ice-{\it i} |
144 |
< |
unit it is extended in the direction of the (001) face and compressed |
145 |
< |
along the other two faces. |
141 |
> |
be noted that a second version of Ice-{\it i} (Ice-{\it i}$^\prime$) |
142 |
> |
was used in calculations involving SPC/E, TIP4P, and TIP5P. The unit |
143 |
> |
cell of this crystal (Fig. \ref{iceiCell}B) is similar to the Ice-{\it |
144 |
> |
i} unit it is extended in the direction of the (001) face and |
145 |
> |
compressed along the other two faces. There is typically a small |
146 |
> |
distortion of proton ordered Ice-{\it i}$^\prime$ that converts the |
147 |
> |
normally square tetramer into a rhombus with alternating approximately |
148 |
> |
85 and 95 degree angles. The degree of this distortion is model |
149 |
> |
dependent and significant enough to split the tetramer diagonal |
150 |
> |
location peak in the radial distribution function. |
151 |
|
|
152 |
|
\section{Methods} |
153 |
|
|