[gmx-users] REMD run showing temperature range more than the equilibrated.

[suhani nagpal]

Hi all !

well, I'm working on REMD with 96 replicas, with temperature range 280K to
425.04K.

The NVT equilibration works well and graphs plotted show almost the
required temperature after equilibration.

Then, after 3 ns of remd run , the edr -> xvg files show initial
temperature atleast 40 -50 units up , and then gradually reduces to it's
temperature.

for example
replica 0 has 280 temperature , for initial 40 ps, it shows temperature up
till 335K an then, decline.

and around 21st to 22nd replica, the exchange probability is varying a lot
from 20% to 60%.

so, my queries are

 how to resolve this temperature issue and why is the exchange probability
so abrupt at 21-22 replica ?


Thanks