[gmx-users] Umbrella sampling and PMF calculations

[Alex]

>
> I find that surprising.  Please provide the full, exact error and your
>> pull settings.  All of the geometries should work with zero or non-zero
>> pull rates. But I admit, it has been many years since I used GROMACS with
>> the pull code.
>>
>
Simply take your pull code from the tutorial and replace 'distance' with
'direction-periodic' or 'cylinder' (along with some r0/r1). The error is
that the pull vector cannot be (0 0 0), do not remember the exact text.
Setting the pull rate to something like 1e-12 results in the same error.
Our cluster is down for maintenance until Monday, will give you the exact
excerpt, if needed.

>
>
>>
>>
> Old GROMACS versions had a "position" geometry that was the go-to for
> membrane/slab/layered systems and worked quite nicely, but that's gone now,
> replaced by other options that I've never used.


How old? I have 5.0.4 on another machine here...