My question is related to the question here but not exactly the same. The studies which have looked into the excited states of molecules have generally done it by parameterizing the ground-state and excited state of the molecule of interest, and then using those parameters to run independent MD simulations,as described here and here. However, let's say that I am interested in starting from a ground-state simulation, and would like to go towards the excited state during the simulation, and then come back to the ground state. My current methodology is to do this in parts:
- Start the simulation with the ground-state parameters.
- Let the simulation run for N nanoseconds and stop the simulation.
- Restart the simulation using excited-state parameters, and let it run for the next M nanoseconds.
- Stop the simulation and change back to ground-state parameters and continue of the remainder of the simulation.
The idea behind this methodology is to assume that radiation is introduced as a kind of perturbation to the system (that's why there is no second minimization). Is there a way where I can smoothly vary between the ground-state and excited-state parameters?