[gmx-users] Doubt regarding enthalpy calculation

[Tushar Ranjan Moharana]

Hi all,
I want to calculate enthalpy between 2 energy group (I wanted to calculate
interaction energy, however I understood that it is challenging. I will
appreciate if someone proves me wrong). I achieved it by performing MD
simulation (energy minimization, NVT, NPT production run). I made different
energy group and rerun the production run and extract LJ  and coulombic
(both short and 14) interaction between them. I got enthalpy by adding the
above terms. Now my doubts are:

1) Am I doing anything wrong or in appropriate?
2) Production run is as mentioned in tutorial by Justine A Lemkule. I want
to know which ensemble it is (NVT, NPT or NVE) and what is the optimum
ensemble to calculate enthalpy (or energy ).
3) Is the enthalpy between one molecule and rest of the system calculated
by above method, if correct, is enthalpy difference between the molecule in
isolation and in the given environment?


Kindly help me understand the above.
Thanks a lot


"A society with free knowledge is better than a society with free food"
-- 
Tushar Ranjan Moharana
B. Tech, NIT Warangal
Ph D Student, CCMB