I have a problem with temeperature weighting for Langevin Thermostat: I
try to heat slowly, but on the output the temperature seems to rise very
rapidly.
Here is my input script:
Molecular dynamics script
&cntrl
imin=0
nstlim=400000, ntt=3,gamma_ln=1,
ntpr=50, pencut=0.1, ntwx = 50,
ntwe =50,
cut=16,
vlimit=10,
ntb=0,
ntc=2, nmropt=1,
&end
constrain ca
10
search
CA * M *
find
end
end
&ewald
eedmeth=5
&end
&wt
type='TEMP0', istep1=0, istep2=35000, value1=0.0, value2=100.0, /
&wt
type='TEMP0', istep1=35001, istep2=70000, value1=100.0, value2=200.0, /
&wt
type='TEMP0', istep1=70001, istep2=100000, value1=200.0, value2=300.0,
/
&wt
type='TEMP0', istep1=100001, istep2=400000, value1=300.0, value2=300.0,
/
&wt
type='END' /
**********************************
The output looks like this:
**********************************
--------------------------------------------------------------------------------
2. CONTROL DATA FOR THE RUN
--------------------------------------------------------------------------------
General flags:
imin = 0, nmropt = 1
Nature and format of input:
ntx = 1, irest = 0, ntrx = 1
Nature and format of output:
ntxo = 1, ntpr = 50, ntrx = 1, ntwr =
500
iwrap = 0, ntwx = 50, ntwv = 0, ntwe =
50
ioutfm = 0, ntwprt = 0, idecomp = 0, rbornstat=
0
Potential function:
ntf = 1, ntb = 0, igb = 0, nsnb =
25
ipol = 0, gbsa = 0, iesp = 0
dielc = 1.00000, cut = 16.00000, intdiel = 1.00000
scnb = 2.00000, scee = 1.20000
Frozen or restrained atoms:
ibelly = 0, ntr = 0
Molecular dynamics:
nstlim = 400000, nscm = 1000, nrespa = 1
t = 0.00000, dt = 0.00100, vlimit = 10.00000
Langevin dynamics temperature regulation:
ig = 71277
temp0 = 300.00000, tempi = 0.00000, gamma_ln= 1.00000
SHAKE:
ntc = 2, jfastw = 0
tol = 0.00001
NMR refinement options:
iscale = 0, noeskp = 1, ipnlty = 1, mxsub =
1
scalm = 100.00000, pencut = 0.10000, tausw = 0.10000
--------------------------------------------------------------------------------
3. ATOMIC COORDINATES AND VELOCITIES
--------------------------------------------------------------------------------
begin time read from input coords = 0.000 ps
Begin reading energy term weight changes/NMR restraints
WEIGHT CHANGES:
TEMP0 0 35000 0.000000 100.000000 0 0
TEMP0 35001 70000 100.000000 200.000000 0 0
TEMP0 70001 100000 200.000000 300.000000 0 0
TEMP0 100001 400000 300.000000 300.000000 0 0
RESTRAINTS:
** No restraint defined **
Done reading weight changes/NMR restraints
..................
******************************
The temperature evolution is :
******************************
NSTEP = 0 TIME(PS) = 0.000 TEMP(K) = 0.00 PRESS =
0.0
NSTEP = 50 TIME(PS) = 0.050 TEMP(K) = 15.22 PRESS =
0.0
NSTEP = 100 TIME(PS) = 0.100 TEMP(K) = 28.32 PRESS =
0.0
NSTEP = 150 TIME(PS) = 0.150 TEMP(K) = 41.17 PRESS =
0.0
NSTEP = 200 TIME(PS) = 0.200 TEMP(K) = 53.06 PRESS =
0.0
NSTEP = 250 TIME(PS) = 0.250 TEMP(K) = 66.68 PRESS =
0.0
NSTEP = 300 TIME(PS) = 0.300 TEMP(K) = 78.52 PRESS =
0.0
NSTEP = 350 TIME(PS) = 0.350 TEMP(K) = 89.48 PRESS =
0.0
NSTEP = 400 TIME(PS) = 0.400 TEMP(K) = 100.42 PRESS =
0.0
I hope you can help.
-------------------------------------------------------
Madalin G. Giambasu
Junior Research Assistant
Institute of Biochemistry of Romanian Academy of Science
Splaiul Independentei 296, 060031, Bucharest 17, Romania
Phone: (+4)021.223.90.69; FAX: (+4)021.223.90.68
-------------------------------------------------------
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Received on Thu Sep 02 2004 - 01:15:12 PDT
