Dear Amber users,
I have been running Gibbs for imidazole in water. I get identical
forward and reverse F_energy values which I thought should be of opposite sign.
I did not use the IDWIDE option to turn off the double-wide
sampling.
My input is the following:
-------
imidazole in h20; shake; CORC; no electrost. decoupling; dyn mod wind 1->0
&cntrl
irest = 0, ntx = 7,
NSTLIM = -1, DT = 0.001,
NTB = 2, NTP = 1, NPSCAL = 1,
CUT = 8.0, NSNB = 25, SCEE = 1.2, IDIEL = 1, DIELC=1.0,
NTC = 3, NTF = 3, TOL = .00001,
NTPR = 10,
NCORC = 1, IELPER = 0,
ISLDYN = -2, ALMDA = 1.0,
NSTMEQ = 1000, NSTMUL = 1000,
DLMIN =0.1d-9, DLMAX = 0.05,
&end
-----------------------------------
Here is the end of the output:
nb-update: total= 162999 hbpair= 70548 pert= 4266
NO DYNAMICALLY MODIFIED WINDOWS COLLECTED SINCE LAST REPORT
NSTEP =1766860 TIME(PS) =1766.860 TEMP(K) = 314.101 PRESS = 7.054
Etotal = -3967.66755 Kinetic = 966.22876 Potential = -4933.89631
Bond = 0.00000 Angle = 21.45533 Dihed = 0.99531
1-4 VdW = 0.13262 1-4 Elec= -18.39581 Van d Waal = 757.37148
Elect. = -5695.45525 H-bond = 0.00000 Constraint = 0.00000
Ekcmt = 482.15438 VirT = 479.76242 Volume = 15704.68681
Density = 0.98402
Current Lambda = 0.999900
Last F.E. update: Lambda = 0.999900 Step = 1764740 Method = F.E.P.
Accumulated "forward" quantities (Regular)
Lam+d_lam = 0.999900 F_energy = 1340.30551
Accumulated "reverse" quantities (Regular)
Lam-d_lam = 0.999900 F_energy = 1340.30551
(Note: values are unchanged from last report)
Also the value of the F_energy is very large for the beginning of the
calculation. Is this normal ? The charges come from mp2/6-31G*.
No electrostatic decoupling is used. The perturb. charges used are the
same as the atomic charges from ab initio.
thanks,
Alessandra
Received on Tue Nov 14 2000 - 15:12:00 PST
