Updated cyclix-MLFF arxiv paper in Manual_mlff

doc/.LaTeX/mlff/Introduction.tex

@@ -23,7 +23,7 @@
 \begin{frame}[allowframebreaks]{\textbf{Citation}} \label{Citation}
 If you publish work using/regarding MLFF in SPARC, please cite some of the following articles, particularly those that are most relevant to your work:
 \begin{itemize}
- \item \url{https://doi.org/10.1063/5.0180541}
+ \item \url{https://doi.org/10.1063/5.0180541}, \url{https://doi.org/10.48550/arXiv.2408.07554} (Cyclix-DFT)
 
 \end{itemize}
 \end{frame}