> It doesn't sound like this should be happening; we would need more details
> (e.g. actual input files) to figure out what is going on. What is your
> value of vdwmeth? If this is turned on, you would get a vdW term, although
> it would not be accurate, since it assumes a continuous density.
>
> ..dac
Here is my input file, just one-step energy calculation, I didnot switch
on the vdwmeth.
# sander: Eqlbrtn of waters const T , SHAKE, cut=12.0
&cntrl
irest=0, ntx=1,
imin=1,
maxcyc=0,ncyc=100,ntmin=2,
nstlim=1,
ntpr=1, ntwr=500,
t=0.0, dt=0.0020, vlimit=20.0,
ntt=1, temp0=300.0, dtemp=0.0, tautp=0.2,
ntb=2, ntp=1, pres0=1.0, comp=44.5, taup=0.5,
ntc=2, tol=0.0001, ntf=2, nsnb=10,
cut=9.0,scnb=2.0, scee=1.2,
ntr=0,
&end
Group input for restrained atoms
900.0
RES 1 29
END
END
$$$$ And this is the output file (part)
FINAL RESULTS
NSTEP ENERGY RMS GMAX NAME NUMBER
1 -2.1114E-02 3.7289E-02 5.8693E-02 O 1
BOND = 0.0000 ANGLE = 0.0000 DIHED =
0.0000
VDWAALS = -0.0002 EEL = -0.0209 HBOND =
0.0000
1-4 VDW = 0.0000 1-4 EEL = 0.0000 CONSTRAINT =
0.0000
|
| ELAPSED TIME = 0.250 TOTAL TIME = 0.250
When I change the cut=3.0
The VDWAALS term is larger
NSTEP ENERGY RMS GMAX NAME NUMBER
1 -2.1656E+00 4.8310E+00 6.6157E+00 O 1
BOND = 0.0000 ANGLE = 0.0000 DIHED =
0.0000
VDWAALS = -0.0058 EEL = -2.1599 HBOND =
0.0000
1-4 VDW = 0.0000 1-4 EEL = 0.0000 CONSTRAINT =
0.0000
|
Received on Mon Mar 10 2003 - 07:53:01 PST
