Energy Reaction Path MERP

For describing the dissociation of fer-butyl-chloride (tButCl), we performed MC calculations on fBut+, CF and tetramethylammonium, (CH3)4N+ (TMA+). TMA+ is used as a benchmark because the experimental hydration energy of fBut+ is unknown. We calculated the solvated minimal energy reaction path (MERP) as obtained from the gas phase, i.e., the Cl atom is stepwise removed from the central carbon atom, while the geometry of the fBut group was optimized. 

Figure 3-16. Minimum energy reaction path (MERP) for hydrolysis of ter-butyl-chloride (tBut) in water. Calculated was the potential of mean force for 15 points along the vacuum MERP of tBut immersed in 124 water molecules. For symbols see text...

B3LYP = Becke s 3-parameter exchange functional with the Lee, Yang, and Parr correlation functional MERP = minimum energy reaction path QCISD(T) = quadratic configuration interaction for single and double substitutions and a contribution from triple substitutions. 

---