[gmx-users] g_wham error in umbrella simulation

[Justin Lemkul]

On 11/8/16 9:50 AM, diana p wrote:
> Dear all
> I am doing an umbrella simulation by using the pull code in Gromacs
> 4.6.5 to calculate the PMF. The pull parameters are the following:
>
> ;Pull code
> pull                    = constant_force
> pull_geometry  = position
> pull_dim            = N N Ypull_start           = no
> pull_ngroups     = 1pull_group0       = GRApull_group1       =
> UNKpull_rate1          = 0.01     pull_k1              = 1000
> pull_vec1          = 0.0 0.0 1.0
>
> When i run the WHAM with the Command line:
> g_wham -it tpr-files.dat -if pullf-files.dat -o -hist -unit kCal
> it gave me the following error:
>
> Fatal error: This is not a tpr of an umbrella simulation. Found pull type
> "constant-force" (ir.ePull= 3)
>
> I would be more than pleased if someone could guid me.

The error is pretty explicit - you didn't do umbrella sampling.  You applied a 
constant biasing force.  To do umbrella sampling, you need "pull = umbrella" in 
the .mdp file.

-Justin

-- 
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Justin A. Lemkul, Ph.D.
Ruth L. Kirschstein NRSA Postdoctoral Fellow

Department of Pharmaceutical Sciences
School of Pharmacy
Health Sciences Facility II, Room 629
University of Maryland, Baltimore
20 Penn St.
Baltimore, MD 21201

jalemkul at outerbanks.umaryland.edu | (410) 706-7441
http://mackerell.umaryland.edu/~jalemkul

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