AMBER Archive (2004)

Subject: AMBER: NMR restraints-Floating point exception

From: John (john.dalmaris_at_imperial.ac.uk)
Date: Wed Feb 25 2004 - 08:44:52 CST

Hello,

 

I want to use some NMR restraints in a simulation. The same simulation
without the restraints runs fine. I followed the Refinement of a DNA Duplex
tutorial to prepare the restraint file (distance and torsion angle
restraints). When I introduce the restraints I get the following message:

 

[1]+ Floating point exception/usr/local/amber7/exe/sander -O -i...

 

I have also tried to use only one restraint in order to minimise the
possibility of an error but I still get the same message. Here is the input
file I used:

 

&cntrl

     imin=0, ntx=1, nmropt=1, ipnlty=1, pencut=-0.001,

     ntwr=1000, ntwx=200,

     ntf=2, ntb=2, cut=12.0, ibelly=0,

     nstlim=80000, dt=0.001,

     temp0=298.0, tempi=0.0, ntt=1,

     ntp=1, taup=2.0, npscal=1,

     ntc=2,

 &end

 &wt

   type='TEMP0', istep1=0, istep2=10000,

                 value1=0.0, value2=298.0,

 &end

 &wt

   type='TEMP0', istep1=10001, istep2=80000,

                 value1=298.0, value2=298.0,

 &end

 &wt

 type='REST',istep1=0,istep2=10000, value1=0.01,

             value2=1.0, &end

 &wt

 type='REST',istep1=10001,istep2=80000,value1=1.0,

             value2=1.0, &end

 &wt

   type='END' &end

LISTOUT=POUT

DISANG=RST

 

The output file looks like this:

 

WEIGHT CHANGES:

 TEMP0 0 10000 0.000000 300.000000 0 0

 TEMP0 10001 80000 300.000000 300.000000 0 0

 REST 0 10000 0.010000 1.000000 0 0

 REST 10001 80000 1.000000 1.000000 0 0

 

 RESTRAINTS:

 Requested file redirections:

  LISTOUT = POUT

  DISANG = RST

 Restraints will be read from file: RST

 Here are comments from the DISANG input file:

 #

 

 # 1 VAL HA 2 ILE HN 1.8 2.7

 

 

                       Number of restraints read = 57

 

                  Done reading weight changes/NMR restraints

 

 

 Number of triangulated 3-point waters found: 0

 

 

Is the Floating point exception anything else than dividing by zero?

 

Many thanks for the help,

 

John

 

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