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•Find the transition state and calculate the barrier height (ΔV^≠) for the following reaction.
reaction：HNC → HCN
methods : MP2/aug-cc-pVTZ、MP2/6-31+G**

Table1. Barrier height (ΔV^≠) of HNC → HCN by different basis set(MP2/aug-cc-pVTZ、MP2/6-31+G**).

Using higher-level theory (aug-cc-pVTZ) for single-point calculations to correct ΔV≠ can significantly reduce the error in rate constants.

•Calculate the k(rate constant) in different temperatures (at least 3 different temperatures) for the following reaction and plot of ln(k) versus 1000/T then compare with the experimental values. 

reaction：CH₄ +OH․→ H₂O + CH₃․
methods : MP2/aug-cc-pVTZ、MP2/6-31+G**

Figure 1. Arrhenius plot of MP2/aug-cc-pVTZ, MP2/6-31+G**, experimental

The energy at the transition state (TS) is lower than that of the starting material because, during bond breaking, an imaginary frequency is generated.

Table 2. lnk of MP2/aug-cc-pVTZ, MP2/6-31+G**, experimental at different temperature(100 K~600 k).

a: Symposium (International) on Combustion, Volume 20, Issue 1, 1985, Pages 703-713

reaction：CD4 +OH․→ H₂O(1 H will replace by D) + CD₃․

methods : MP2/6-31+G**

Figure 2. Arrhenius plot of MP2/6-31+G**, experimental