Dear amber users,
A week ago, I sent this email to the list, but there is no response. So I
would like to send it again in case there are some people who did not see it.
I have a question about PMF calculation. Basically, I have performed a PMF
calculation on two torsion angles with Gibbs, and I'd like to want to
know how large the energy penalty would be for this conformational change.
We expected to see a large value, but the calculated free energy is pretty
small. In my output file, we found there was something which looks really
suspicious: All the energy terms are zero except CORC...
    ELEC =      0.000    NONB =      0.000    14NB =      0.000
    14EL =      0.000    BADH =      0.000    CORC =      0.108
    EPOL =      0.000    E3bod=      0.000
  Constrained Internals at Last F.E. Update          Lam       L+d_L
L-d_L
 H1  (3352)-C1  (3351)-O1  (3353)-C7  (3354)       -27.3650  -26.4000
-28.3300
 C1  (3351)-O1  (3353)-C7  (3354)-C8  (3355)      -123.7200 -125.0000
-122.4400
Could anyone tell me what has gone wrong with my calculation? Why
ELEC, NONB, 14NB... are all Zero? Thanks for your attention. Any
suggestion would be greatly appreciated!
-----------------------------------------
Here is my input file:
 &cntrl
    timlim = 0.1000000E+09 , irest  = 1             , ibelly = 0
,
    ichdna = 0             , ipol   = 0             , i3bod  = 0
,
    iewald = 0             ,
    ntx    = 7             , ntxo   = 1             , ig     = 71277
,
    tempi  = 10.0000      , heat   = 0.0000000E+00 ,
    ntb    = 2             , iftres = 0             , boxx(1)=
0.0000000E+00 ,
    boxx(2)= 0.0000000E+00 , boxx(3)= 0.0000000E+00 , betar  =
0.0000000E+00 ,
    ibxrd  = 0             ,
    nrun   = 21            , ntt    = 5             , temp0  = 298.0000
,
    dtemp  = 999.0000      , tautp  = 0.5000000     , tauts  = 0.5000000
,
    isolvp = 0             , nsel   = 0             , dtuse  = 0.5000000
,
    ntp    = 1             , npscal = 0             , pres0  = 1.000000
,
    comp   = 44.60000      , taup   = 0.2000000     ,
    ndfmin = 0             , ntcm   = 0             , nscm   = -1
,
    istay  = 0             , nstay  = 0             , isvat  = 1
,
    nstlim = 25000         , init   = 4             , ntu    = 1
,
    t      = 0.0000000E+00 , dt     = 0.1000000E-02 , vlimit = 20.00000
,
    ivemax = 0             ,
    ntc    = 3             , ntcc   = 0             , nconp  = 0
,
    tol    = 0.1000000E-07 , tolr2  = 0.1000000E-03 , ncorc  = 1
,
    ishkfl = 6             , itimth = 0             , jfastw = 0
,
    ntf    = 3             , ntid   = 0             , ntn    = 3
,
    ntnb   = 1             , nsnb   = 25            , idiel  = 1
,
    inbper = 0             , ielper = 0             , imgslt = 0
,
    idsx0  = 400           , itrslu = 1             , ioleps = 0
,
    intprt = 5             , itip   = 0             ,
    cut    = 10.00000      , scnb   = 2.000000      , scee   = 1.200000
,
    dielc  = 1.000000      , cut2nd = 0.0000000E+00 , cutprt =
0.0000000E+00 ,
    ntpr   = 500000        , ntwx   = -1              , ntwv   = -1
,
    ntwe   = -1            , ntwxm  = 0             , ntwvm  = 0
,
    ntwem  = 0             , ntpp   = 0             , ioutfm = 0
,
    isande = 1             , iperat = 0             , iatcmp = 0
,
    ntatdp = 0             , icmpdr = 0             , ncmpdr = 0
,
    ntwprt = -1             , ntwpr0 = 0             ,
    ntr    = 0             , nrc    = 0             , ntrx   = 1
,
    taur   = 0.1000000     , intr   = 2             , ibigm  = 0
,
    nmrmax = 0             , iwtmax = 0             , isftrp = 0
,
    rwell  = 4.000000      ,
    iftime = 0             , ctimt  = 40.00000      , almda  = 1.000000
,
    almdel = 0.5000000E-01 , isldyn = -3            , idifrg = 0
,
    nstmeq = 10000         , nstmul = 15000         , ndmpmc = 0
,
    idwide = 1             , ibndlm = 0             ,
    iavslp = 8             , iavslm = 2             , islp   = 0
,
    corrsl = 0.8000000     , amxmov = 0.1000000E-01 ,
    iavdel = -1            , iavdem = 2             , amxdel = 0.1000000
,
    almdl0 = 0.100000E-02 , dlmin  = 0.1000000E-04 , dlmax  =
0.1000000E-01 ,
    amxrst = 0.9999999E-01 , norsts = 0             , ntsd   = 0
,
    almstp = -1.000000     ,
    nstpe  = 10000         , nstpa  = 15000         , dte    =
0.1000000E-02 ,
    dta    = 0.1000000E-02 ,
    ivcap  = 2             , natcap = 0             , fcap   = 1.500000
,
 &end
 3352  3351  3353  3354     0     1     2   1.00000   0.00000
   0.00000 -26.40000   0.00000 -45.70000    0    0
 3351  3353  3354  3355     0     1     2   1.00000   0.00000
   0.00000-125.00000   0.00000 -99.40000    0    0
-------------------------------------------------
Thanks in advance.
Xiaojian Tan
-----------------------------------------------------------------------
The AMBER Mail Reflector
To post, send mail to amber.scripps.edu
To unsubscribe, send "unsubscribe amber" to majordomo.scripps.edu
Received on Tue Jul 15 2003 - 18:53:01 PDT