AMBER Archive (2002)

Subject: vlimit exceeded

From: A. Hungie (hungie01_at_hotmail.com)
Date: Wed Jun 12 2002 - 04:49:44 CDT

Dear Amber users,

I tried to run MD by constraint some atoms (NTR=1). I got an error message
"vlimit exceeded" at beginning of dynamics. An input and output are as below

==> mdin
*********************
dynamics
&cntrl
  ntx = 1, irest = 0, nmropt = 0,
  imin = 0, nstlim = 10000,
  dt = 0.002,
  ntcm = 1, nscm = 2500,
  ntpr = 20, ntwr = 500,
  ntb = 2, ntp = 1,
  ntc = 2, tol = 0.000001,
  ntf = 2,
  ibelly = 0, ntr = 1,
  temp0 = 300.0, tempi = 300.0,
  ntt = 1, vlimit = 20.0,
&end

&ewald
  a = 42.2774713, b = 43.6275041, c = 67.0496168,
  nfft1 = 45, nfft2 = 45, nfft3 = 72,
&end
Constrain G6
5000.0
ATOM 171 185
END
Constrain G8
5000.0
ATOM 236 250
END
END

*********************
==> output

NSTEP = 0 TIME(PS) = 0.000 TEMP(K) = 435.47 PRESS = -5283.28
Etot = -49484.9577 EKtot = 10822.6043 EPtot = -60307.5620
.
.
. Density = 1.0308
Ewald error estimate: 0.1386E-03
-----------------------------------------------------------

vlimit exceeded for step 2; vmax = 271.116268

     COORDINATE RESETTING CANNOT BE ACCOMPLISHED,
     DEVIATION IS TOO LARGE
     NITER, NIT, LL, I AND J ARE : 0 1 65 181 182

*************

However, when I changed NTR from 1 to 0 (no constrain) and removed constrain
parameters (last 10 lines in mdin), it worked fine.

Could you please give me any suggestion?

Many thanks in advance.

Hungie.

_________________________________________________________________
Send and receive Hotmail on your mobile device: http://mobile.msn.com