Hello, I would like to determine the time for a reaction (reactant through TS to product) using AIMD and compare it to experimental results. I started from the TS then to determine the reaction time from TS to reactant and to product. I will run 100 times for each, then the total reaction time should be the sum of the average for each reaction direction. But I have two questions in using QChem for AIMD.
(1) First, I run the frequency calculation at TS. Then, in the BOMD step, I use AIMD_INIT_VELOC=ZPE to include and partition ZPVE among the non-imaginary vibrational modes. In addition, I need to specify the "transition vector energy” through REM_AIMD_KINETIC_ENERGY. How do I determine the value for REM_AIMD_KINETIC_ENERGY?
(2) How do I control the motion along the transition vector in the direction toward the product or reactant?
I also tried to use Quasiclassical MD by setting AIMD_INIT_VELOC=quasiclassical. But Quasiclassical MD is not yet supported for transition states in QChem.