AWH using multiwalkers

User discussions
1

GROMACS version: 2020.4
GROMACS modification: No

Dear all,

I’m trying to use AWH method for calculating the PMF with awh-share-multisim on. From the manual I got we have to add this two commands to our mdp paramter file:
awh-share-multisim = yes ; Share bias across simulations
awh1-share-group = 1 ; Non-zero share group index

Now I created several folders and put the tpr file into each of them and mdrun with -multidir option, which basically started the same simulation several times simultaneously. The results were exactly the same as though I run one simulation.

Should I prepare simulations with different initial configurations (e.g. configurations that have different distances along the reaction coordinate) and put them in the folders as multiwalkers?

In any case, how should I extract the results after it’s done? Does an edr file from one of the folders have all the information of all the folders in itself? If not, how can we pass several edr files into “gmx awh”?

Thank you in advance

Ehsan

2

When AWH is sharing, the log file should tell you that AWH is sharing the bias over N simulations. Since there is only one bias, each simulation outputs the same bias and free-energy.

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