Hi all,
I'm looking for an "GIBBS expert". I tried to run gibbs free energy
simulation of two DNA bases in water TIP3P box. Both PME (IEWALD=1)
and PMF (NCORC=1) options were turned on, but results from DMW Free energy
perturbation and DMW Termodynamics integration were completely different (
59 nad 78 kcal/mol). Total simulation time was 500ps. In vacuo everything
goes O.K., the agreement between FEP and TI is about 0.1 - 0.2 kcal/mol.
Thanks for any suggestion !
F. Ryjacek
ryjacek_at_indy.jh-inst.cas.cz
Here is the input for TI :
  
TITLE: A...FT to A..THY h2o box
 &cntrl
    timlim = 9999999.0      , irest  = 0             , ibelly = 0             ,
    ichdna = 0             , ipol   = 0             , i3bod  = 0             ,
    iewald = 1             , 
 
    ntx    = 1             , ntxo   = 1             , ig     = 71277         ,
    tempi  = 100.0000      , heat   = 0.000000      , 
 
    ntb    = 2             , iftres = 1             , boxx(1)= 0.000000      ,
    boxx(2)= 0.000000      , boxx(3)= 0.000000      , betar  = 0.000000      ,
    ibxrd  = 0             , 
 
    nrun   = 1             , ntt    = 5             , temp0  = 298.0000      ,
    dtemp  = 999.0000      , tautp  = 0.2000000     , tauts  = 0.2000000     ,
    isolvp = 0             , nsel   = 0             , dtuse  = 0.5000000     ,
 
    ntp    = 1             , npscal = 0             , pres0  = 1.000000      ,
    comp   = 44.60000      , taup   = 1.000000      , 
 
    ndfmin = 0             , ntcm   = 0             , nscm   = -1          ,
    istay  = 0             , nstay  = 0             , isvat  = 1             ,
 
    nstlim = -1            , init   = 3             , ntu    = 1             ,
    t      = 0.000000      , dt     = 0.1000000E-02 , vlimit = 0.000000      ,
    ivemax = 0             , 
 
    ntc    = 1             , ntcc   = 0             , nconp  = 0             ,
    tol    = 0.1000000E-02 , tolr2  = 0.1000000E-01 , ncorc  = 1             ,
    ishkfl = 1             , itimth = 0             , jfastw = 0             ,
 
    ntf    = 1             , ntid   = 0             , ntn    = 3             ,
    ntnb   = 1             , nsnb   = 500          , idiel  = 1             ,
    inbper = 0             , ielper = 0             , imgslt = 0             ,
    idsx0  = 0             , itrslu = 1             , ioleps = 0             ,
    intprt = 5             , itip   = 0             , 
 
    cut    = 7.00000       , scnb   = 2.000000      , scee   = 1.200000      ,
    dielc  = 1.000000      , cut2nd = 0.000000      , cutprt = 0.000000      ,
 
    ntpr   = 500           , ntwx   = 500           , ntwv   = 500           ,
    ntwe   = 500           , ntwxm  = 0             , ntwvm  = 0             ,
    ntwem  = 0             , ntpp   = 0             , ioutfm = 0             ,
    isande = 1             , iperat = 2             , iatcmp = 1             ,
    ntatdp = 100            , icmpdr = 0             , ncmpdr = 0             ,
    ntwprt = 1000          , ntwpr0 = 0             , 
 
    ntr    = 0             , nrc    = 0             , ntrx   = 1             ,
    taur   = 0.1000000     , intr   = 5             , ibigm  = 1             ,
    nmrmax = 0             , iwtmax = 0             , isftrp = 0             ,
    rwell  = 4.000000      , 
 
    iftime = 0             , ctimt  = 40.00000      , almda  = 0.000000      ,
    almdel = 0.1000000E-01 , isldyn = +2            , idifrg = 1             ,
    nstmeq = 10           , nstmul = 50           , ndmpmc = 100           ,
    idwide = 0             , ibndlm = 0             , 
 
    iavslp = 8            , iavslm = 2             , islp   = 0             ,
    corrsl = 0.9500000     , amxmov = 0.1000000E-01 , 
 
    iavdel = -1            , iavdem = 2             , amxdel = 0.1000000     ,
 
    almdl0 = 0.1000000E-05 , dlmin  = 0.1000000E-03 , dlmax  = 0.1000000E-01 ,
    amxrst = 0.2000000     , norsts = 0             , ntsd   = 0             ,
    almstp = -1.000000     , 
 
    nstpe  = 100           , nstpa  = 100           , dte    = 0.1000000E-02 ,
    dta    = 0.1000000E-02 , 
 
    ivcap  = 2             , natcap = 0             , fcap   = 1.500000      ,
 
 &end
 28.83319  22.127913  18.149101  90.0  90.0  90.0
 30  24  20  4  0  0  0
 0.00001
    7    11    27    29     0     0     0    1.00000   0.00000                  
 100.00000 180.00000 100.00000 180.00000    0    0                              
   12    11    27    25     0     0     0    1.00000   0.00000                  
 100.00000 180.00000 100.00000 180.00000    0    0                              
   14    12    11    27     0     0     0    1.00000   0.00000                  
 100.00000 180.00000 100.00000 180.00000    0    0                              
    6     7    11    27     0     0     0    1.00000   0.00000                  
 100.00000 180.00000 100.00000 180.00000    0    0                              
   11    27     0     0     0     0     0    1.00000   0.00000                  
  10.00000   2.97700  10.00000   3.65600    0    0                              
 
Received on Thu Oct 21 1999 - 02:32:03 PDT