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|
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|
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|
\subsection{\label{Sec:pbc}Periodic Boundary Conditions} |
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+ |
|
| 401 |
+ |
\newcommand{\roundme}{\operatorname{round}} |
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|
| 403 |
|
\textit{Periodic boundary conditions} are widely used to simulate truly |
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|
macroscopic systems with a relatively small number of particles. The |
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|
\end{equation} |
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And then, each element of $\mathbf{s}$ is wrapped to lie between -0.5 to 0.5, |
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|
\begin{equation} |
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< |
s_{i}^{\prime}=s_{i}-round(s_{i}) |
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> |
s_{i}^{\prime}=s_{i}-\roundme(s_{i}) |
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|
\end{equation} |
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|
where |
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|
| 438 |
|
% |
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|
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|
\begin{equation} |
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< |
round(x)=\left\{ |
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< |
\begin{array}[c]{c}% |
| 441 |
> |
\roundme(x)=\left\{ |
| 442 |
> |
\begin{array}{cc} |
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|
\lfloor{x+0.5}\rfloor & \text{if \ }x\geqslant0\\ |
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\lceil{x-0.5}\rceil & \text{otherwise}% |
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|
\end{array} |
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|
\right. |
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\end{equation} |
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+ |
For example, $\roundme(3.6)=4$, $\roundme(3.1)=3$, $\roundme(-3.6)=-4$, |
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+ |
$\roundme(-3.1)=-3$. |
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|
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– |
|
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– |
For example, $round(3.6)=4$,$round(3.1)=3$, $round(-3.6)=-4$, |
| 449 |
– |
$round(-3.1)=-3$. |
| 450 |
– |
|
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Finally, we obtain the minimum image coordinates by transforming back |
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to real space,% |
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|
