This is exactly the right behavior
It is not that the restraint is not working, but rather that is working
perfectly. You told the system to try to put the distance
between atoms 9292 and 7786 between 1.5 and 2 Angstroms. The system
tried it, and succeded, at which point the
Restraint energy is zero, because you are in flat section of your
potential restraint.
Adrian
xuemeiwang1103 wrote:
>
>
> Dear Dr. :
>
> Thanks a lot for your detailed explanation and several useful suggestions .I tried it again ,I found the computer can calculated if I removed ntr=1 and just keep nmropt=1 in my input file,but the strange things happened again,the NMR restraint seems just took effect in the first few steps ,cound you tell me where I went wrong in my input,I really felt very bad about this problem ,thank you very much!
>
> my input:
>
> Stage 1 heating of 1o86 0 to 50K
>
> &cntrl
>
> imin=0,irest=0,ntx=1,
>
> nstlim=5000,dt=0.001,
>
> ntc=2,ntf=2,
>
> ntt=3,gamma_ln=1.0,
>
> tempi=0.0,temp0=50.0,
>
> ntb=1,cut=8,
>
> nmropt=1,
>
> ntpr=250,ntwx=500,ntwr=500,
>
> /
>
> &wt type='REST',istep1=0,istep2=5000,
>
> value1=1.0,value2=1.0,
>
> /
>
> &wt type='END' ,
>
> /
>
> LISTOUT=RST.out
>
> DISANG=dis.RST
>
> ---------------- dis.RST-----------
>
> #DISTANTENT.FILE
>
> &rst
>
> ixpk= 0, nxpk= 0, iat= 9292, 7786, r1= 1.20, r2= 1.50, r3= 2.00, r4= 5.00, rk2=10.0, rk3=10.0, ir6=1,
>
> /
>
> Outputfile :
>
> NSTEP = 0 TIME(PS) = 0.000 TEMP(K) = 0.00 PRESS = 0.0
>
> Etot = -354165.8192 EKtot = 0.0000 EPtot = -354165.8192
>
> BOND = 323.2417 ANGLE = 1484.8635 DIHED = 2630.5202
>
> 1-4 NB = 1853.1531 1-4 EEL = 23829.9363 VDWAALS = 62903.2679
>
> EELEC = -447237.1261 EHBOND = 0.0000 RESTRAINT = 46.3241
>
> EAMBER (non-restraint) = -354212.1433
>
> Ewald error estimate: 0.1509E-03
>
> ------------------------------------------------------------------------------
>
> NMR restraints: Bond = 46.324 Angle = 0.000 Torsion = 0.000
>
> NSTEP = 250 TIME(PS) = 0.250 TEMP(K) = 16.33 PRESS = 0.0
>
> Etot = -300871.8202 EKtot = 2700.2781 EPtot = -303572.0983
>
> BOND = 374.7332 ANGLE = 1603.3394 DIHED = 2663.7262
>
> 1-4 NB = 1865.1801 1-4 EEL = 23834.0649 VDWAALS = 46987.7396
>
> EELEC = -380900.8816 EHBOND = 0.0000 RESTRAINT = 0.0000
>
> Ewald error estimate: 0.3079E-03
>
> ------------------------------------------------------------------------------
>
> NMR restraints: Bond = 0.000 Angle = 0.000 Torsion = 0.000
>
> NSTEP = 500 TIME(PS) = 0.500 TEMP(K) = 25.26 PRESS = 0.0
>
> Etot = -298494.3179 EKtot = 4176.6006 EPtot = -302670.9184
>
> BOND = 408.2542 ANGLE = 1694.0090 DIHED = 2691.5324
>
> 1-4 NB = 1886.3935 1-4 EEL = 23852.1110 VDWAALS = 48006.3952
>
> EELEC = -381209.6138 EHBOND = 0.0000 RESTRAINT = 0.0000
>
> Ewald error estimate: 0.2284E-03
>
> ------------------------------------------------------------------------------
>
> NMR restraints: Bond = 0.000 Angle = 0.000 Torsion = 0.000
>
> ===============================================================================
>
>
>
>
>
>
>
> ------------------------------------------------------------------------
>
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--
Dr. Adrian E. Roitberg
Associate Professor
Quantum Theory Project
Department of Chemistry
Senior Editor. Journal of Physical Chemistry
American Chemical Society
University of Florida PHONE 352 392-6972
P.O. Box 118435 FAX 352 392-8722
Gainesville, FL 32611-8435 Email adrian.qtp.ufl.edu
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Received on Wed Oct 28 2009 - 07:30:02 PDT
