AMBER Archive (2002)

Subject: Re: message during minimization

From: darden (darden_at_gamera.niehs.nih.gov)
Date: Wed Dec 18 2002 - 10:24:48 CST

Dear Iona
Can't tell you why the minimization died with no message. The message you
got is normal and should appear always. Its just a self test for the
interpolation of erfc. (interpolation is used since calculation of erfc is
rather slow). Finding out about the the failed minimization looks like it
would require an extensive debug session on your machine.
Tom D
 On Tue, 17 Dec 2002, Ioana Cozmuta wrote:

> Hi amber users,
>
> I am trying to run a minimization with amber7 (Origin3000 cluster)
> using the
> max number of processors allowed in amber
> (128) using the following input file
>
> Initial minimization of the water box, 20A, PBC, 9.0 cut
> &cntrl
> ntx = 1, irest = 0, ntxo = 1,
> ntpr = 1,
> ntf = 1, ntb = 1,
> cut = 8.0, scee = 1.2,
> ibelly = 0, ntr = 0,
> imin = 1,
> maxcyc = 300,
> ncyc = 50,
> ntmin = 1, dx0 = 0.1, dxm = 0.5, drms = 0.0001,
> &end
>
>
> There is no real error message just the following:
>
>
> APPROXIMATING switch and d/dx switch using CUBIC SPLINE INTERPOLATION
> using 5000.0 points per unit in tabled values
> TESTING RELATIVE ERROR over r ranging from 0.0 to cutoff | CHECK
> switch(x): max rel err = 0.2088E-14 at 2.598900 | CHECK d/dx switch(x):
> max rel err = 0.7671E-11 at 2.757160
> ---------------------------------------------------
>
> I wonder what it means and why does my run stop?
>
> If I decrease the number of processors to 4 then my minimization runs
> with no problems.
>
> Thank you,
> Ioana
>