AMBER Archive (2001)

Subject: Blowup problem

From: txyang (txyang_at_lyman.q.t.u-tokyo.ac.jp)
Date: Thu Apr 05 2001 - 02:12:45 CDT

Dear all,

I have met a blowup problem with constant pressure when running MD using
Sander_calssic (AMBER6).

     COORDINATE RESETTING CANNOT BE ACCOMPLISHED,
     DEVIATION IS TOO LARGE
     NITER, NIT, LL, I AND J ARE : 0 5 1 2 11
 FATAL ERROR

Someone proposed a bigger box in FAQ. But it seems not work in my case even
if I have enlarge the box size or using constant volume instead of constant
pressure. Would you please help me out? Your response is greatly
appreciated. Thank you very much in advance.

Best wishes,
Tianxiao Yang

The following is my input file.

 &cntrl
  imin = 0, irest = 0, nrun = 1, ntx = 1,
  timlim = 999999, init = 3,
  ntpr = 100, ntwx = 100, ntwv = 100, ntwe = 100,
  nstlim = 300000, nmrmax = 1,
  ntwxm = 0,
  ntwvm = 0, ntwem = 0,
  tempi= 10.0, temp0 = 298.0, IG = 71277, heat = 0.0, tautp = 0.1,
  vlimit = 15.0,
  ntt = 3, npscal = 1, ntb = 2, ntp = 1, PRES0 =1,
  DT = 0.001, taup = 0.02,
  ntf = 2, ntc = 2, idiel = 1, dielc = 1.0, cut = 12.0, ntnb = 1,
  scee = 1.2, iftres = 1,
  ibelly = 0, ntr = 1,
 &end
 &wt
   type='TEMP0', istep1=1, istep2=20000,
                 value1=10.0, value2=100.0,
 &end
&wt
   type='TEMP0', istep1=20000, istep2=50000,
                 value1=100.0, value2=298.0,
&end
 &wt
   type='TEMP0', istep1=50000, istep2=300000,
                 value1=298.0, value2=298.0,
 &end
 &wt
   type='END',
 &end
 &rst
   iat=0,
 &end
 Hold the solute fixed
100.0
RES 1
END
END