I am having trouble understanding how (and even whether it's possible) to get free energy from kinetic and potential energy.
I have run molecular dynamics simulations (NPT ensemble, CP2K software), but this is a basic thermodynamics question. There's a results file called "energy." The file contains energy-related output: temperature, kinetic and potential energy, and a "conserved" quantity.
(The "conserved quantity" is the sum of the kinetic and potential energies and also the thermostat energies).
From courses a long time ago and reading I have done online, I know that
kinetic energy + potential energy = total energy
I think "total energy" would be the internal energy. It would be great if someone could please confirm/debunk that--I don't know if the situation is distinct for distinct ensembles, for example. Whatever the case, I don't know how it relates to the free energy. I would like to know if I have enough information to calculate the free energy.
If anyone could please point me in the right direction, I would appreciate it. I can't find anything online and maybe that's because I don't even know where to start looking.