Re: Sander_classic output: NAN

From: David A. Case <case.scripps.edu>
Date: Mon, 14 Jul 2003 15:27:17 -0700

On Mon, Jul 14, 2003, pantelo.okstate.edu wrote:

> I am running a simple minimization of RB69, Pol-alpha, using sander_classic.
> Below is my input file. I am using .prmtop and .inpcrd files before any
> water or ions have been added. I am having a problem with my output file
> numbers. After the first run, I get "nan" values for everything. Do you
> think it is a problem with my structure or with my input file?

It looks like a problem with the corrdinates, since the 1-4 interactions
are the ones that are blowing up. It is mostly likely that two atoms have
identical coordinates.

>
> Input:
>
> Relaxation of Hydrogen holding all heavy atoms still
> &cntrl
> ntpr=1,
> ntf=1, idiel=0, dielc=1, scnb=2, scee=1.2, cut=10.0
> imin=1, maxcyc=100, ncyc=100, ntmin=1, ntwe=10, ntwxm=0,
> ntr=1, ntwx=1, ntwem=0,
> &end
> Group input for restraining the Protein and DNA heavy atoms
> 5000

I would suggest using a force constant 100 to 1000 times smaller than that
above.

> FIND
> * * M *
> SEARCH
> RES 1 934
> END
> END
>
>
> Output after one step:
>
> NSTEP ENERGY RMS GMAX NAME NUMBER
> 1 nan nan 3.9408E+08 O 16661
>
> BOND = 903.6790 ANGLE = 2606.6465 DIHED = 8287.9576
> VDWAALS = 23532619.7971 EEL = -24232.1835 HBOND = 0.0000
> 1-4 VDW = nan 1-4 EEL = inf CONSTRAINT = 0.0000
>

...good luck..dac

-- 
==================================================================
David A. Case                     |  e-mail:      case.scripps.edu
Dept. of Molecular Biology, TPC15 |  fax:          +1-858-784-8896
The Scripps Research Institute    |  phone:        +1-858-784-9768
10550 N. Torrey Pines Rd.         |  home page:                   
La Jolla CA 92037  USA            |    http://www.scripps.edu/case
==================================================================
Received on Mon Jul 14 2003 - 23:52:51 PDT
Custom Search