Add reference

Author: davidlmobley

paper/basic_training.bib

@@ -984,3 +984,16 @@ @article{Isele-Holder:2012:J.Chem.Phys.
   year = {2012},
   pages = {174107},
 }
+
+@article{Paliwal:2013:J.Chem.TheoryComput.,
+  title = {Using {{Multistate Reweighting}} to {{Rapidly}} and {{Efficiently Explore Molecular Simulation Parameters Space}} for {{Nonbonded Interactions}}},
+  volume = {9},
+  issn = {1549-9618},
+  doi = {10.1021/ct4005068},
+  number = {11},
+  journal = {J. Chem. Theory Comput.},
+  author = {Paliwal, Himanshu and Shirts, Michael R.},
+  month = nov,
+  year = {2013},
+  pages = {4700-4717},
+}

paper/basic_training.tex

@@ -1105,7 +1105,8 @@ \subsubsection{Grid based Ewald summation}
 Decreasing the cutoff improves the direct space performance but increases the complexity of the reciprocal space calculations. 
 \end{itemize}
 
-
+In principle, it is possible to optimize settings for handling of long-range electrostatics in order to achieve considerable efficiency gains while maintaining accuracy, though this can involve considerable care~\cite{Paliwal:2013:J.Chem.TheoryComput.}. 
+For novice users, we suggest typically using well-validated or default settings for the particular method employed, and only deviating from these with careful consideration and testing.
 
 
 \begin{Checklists*}[p!]