Hello,
Could anybody tell me how temeprature control is performed, when using a
Langevin thermostat in amber8? I suppose that it is implemented as described in
van Gunstern et al., 1981, if I understand the manual correctly. The temperature
control would in this case be derived from the random collision force, that is
taken from a temperature dependant gaussian distribution. 
I suppose simulated annealing could be performed by slowly varying the
temperature of the gaussian distribution yielding the random collision force?
But I think that is not implemented, as my  simulated annealing input file, that
works fine for Berendsen thermostat md, doesn't work for a langevin thermostat md.
Thank you very much in advance!
Pascal
------------------------------------------------------
equilibr 
 &cntrl
     IMIN = 0,
     NMROPT = 1,      
     NTX = 1, 
     IREST = 0,     
     NTPR = 10,
     NTWR = 10000, 
     NTWX = 500, 
     NTF = 1,   
     NTB = 0, 
     DIELC = 1.0, 
     CUT = 1000.0,
     SCNB = 2.0,  
     SCEE = 1.2,
     NSTLIM = 32000000, 
     NSCM = 1000, 
     DT = 0.0015,
     NTT = 3,
     GAMMA_LN = 91,
     TEMPI=0.0
     NTC = 2,    
     TOL = 0.00001,
     NTR = 0, 
     IBELLY = 0,
     IVCAP = 0,
     IGB = 1,     
 &end
 &wt
     TYPE='TEMP0', istep1=0, istep2=400000, value1=0.0, value2=300.0,
 &end
 &wt
     TYPE='TEMP0', istep1=400001, istep2=32000000, value1=300.0, value2=300.0,
 &end  
 &wt
     TYPE='END',
 &end
-----------------------------------------------------------------------
          -------------------------------------------------------
          Amber 8  SANDER                 Scripps/UCSF 2004
          -------------------------------------------------------
| Run on 04/19/2005 at 22:25:28
File Assignments:
|  MDIN: saLang.in                                                             
| MDOUT: mdout                                                                 
|INPCRD: ../../min/mdres.crd                                                   
|  PARM: ../../ff99.top                                                        
|RESTRT: mdres.crd                                                             
|  REFC: refc                                                                  
| MDVEL: mdvel                                                                 
|  MDEN: mden                                                                  
| MDCRD: traj.crd                                                              
|MDINFO: mdinfo                                                                
|INPDIP: inpdip                                                                
|RSTDIP: rstdip                                                                
 
 Here is the input file:
 
equilibr                                                                       
 &cntrl                                                                        
     IMIN = 0,                                                                 
     NMROPT = 1,                                                               
     NTX = 1,                                                                  
     IREST = 0,                                                                
     NTPR = 10,                                                                
     NTWR = 10000,                                                             
     NTWX = 500,                                                               
     NTF = 1,                                                                  
     NTB = 0,                                                                  
     DIELC = 1.0,                                                              
     CUT = 1000.0,                                                             
     SCNB = 2.0,                                                               
     SCEE = 1.2,                                                               
     NSTLIM = 32000000,                                                        
     NSCM = 1000,                                                              
     DT = 0.0015,                                                              
     NTT = 3,                                                                  
     GAMMA_LN = 91,                                                            
     TEMPI=0.0                                                                 
     NTC = 2,                                                                  
     TOL = 0.00001,                                                            
     NTR = 0,                                                                  
     IBELLY = 0,                                                               
     IVCAP = 0,                                                                
     IGB = 1,                                                                  
 &end                                                                          
                                                                               
                                                                               
 &wt                                                                           
     TYPE='TEMP0', istep1=0, istep2=400000, value1=0.0, value2=300.0,          
 &end                                                                          
 &wt                                                                           
     TYPE='TEMP0', istep1=400001, istep2=1000000, value1=300.0, value2=300.0,  
 &end                                                                          
 &wt                                                                           
     TYPE='END',                                                               
 &end                                                                          
                                                                               
                                                                               
                                                                               
--------------------------------------------------------------------------------
   1.  RESOURCE   USE: 
--------------------------------------------------------------------------------
| Flags: MPI                                                                    
| New format PARM file being parsed.
| Version =    1.000 Date = 03/18/05 Time = 18:11:40
 NATOM  =     389 NTYPES =      14 NBONH =     133 MBONA  =     286
 NTHETH =     301 MTHETA =     445 NPHIH =     658 MPHIA  =     812
 NHPARM =       0 NPARM  =       0 NNB   =    2166 NRES   =      12
 NBONA  =     286 NTHETA =     445 NPHIA =     812 NUMBND =      35
 NUMANG =      72 NPTRA  =      39 NATYP =      24 NPHB   =       0
 IFBOX  =       0 NMXRS  =      34 IFCAP =       0 NEXTRA =       0
 NCOPY  =       0
|     Memory Use     Allocated
|     Real               11134
|     Hollerith           2348
|     Integer            40875
|     Max Pairs              1
|     Max Rstack             1
|     Max Istack             1
|       Total              255 kbytes
| Duplicated    0 dihedrals
| Duplicated    0 dihedrals
--------------------------------------------------------------------------------
   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    =      10, ntrx    =       1, ntwr    =   10000
     iwrap   =       0, ntwx    =     500, ntwv    =       0, ntwe    =       0
     ioutfm  =       0, ntwprt  =       0, idecomp =       0, rbornstat=      0
Potential function:
     ntf     =       1, ntb     =       0, igb     =       1, nsnb    =      25
     ipol    =       0, gbsa    =       0, iesp    =       0
     dielc   =   1.00000, cut     =1000.00000, intdiel =   1.00000
     saltcon =   0.00000, offset  =   0.09000, gbalpha=    1.00000
     gbbeta  =   0.00000, gbgamma =   0.00000, surften =   0.00500
     rdt     =   0.00000, rgbmax  =  25.00000
     scnb    =   2.00000, scee    =   1.20000
Frozen or restrained atoms:
     ibelly  =       0, ntr     =       0
Molecular dynamics:
     nstlim  =32000000, nscm    =    1000, nrespa  =       1
     t       =   0.00000, dt      =   0.00150, vlimit  =  20.00000
Langevin dynamics temperature regulation:
     ig      =   71277
     temp0   = 300.00000, tempi   =   0.00000, gamma_ln=  91.00000
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 400000    0.000000  300.000000      0      0
 TEMP0    4000011000000  300.000000  300.000000      0      0
 RESTRAINTS:
                          ** No restraint defined **
                  Done reading weight changes/NMR restraints
 Number of triangulated 3-point waters found:        0
|  Atom division among processors:
|         0     196     389
|  Running AMBER/MPI version on    2 nodes
--------------------------------------------------------------------------------
   4.  RESULTS
--------------------------------------------------------------------------------
 NSTEP =        0   TIME(PS) =       0.000  TEMP(K) =     0.00  PRESS =     0.0
 Etot   =     -2779.4852  EKtot   =         0.0000  EPtot      =     -2779.4852
 BOND   =        19.1296  ANGLE   =        82.2276  DIHED      =       272.9131
 1-4 NB =        95.4341  1-4 EEL =     -1594.9962  VDWAALS    =      -231.1730
 EELEC  =       982.8168  EGB     =     -2405.8371  RESTRAINT  =         0.0000
 ------------------------------------------------------------------------------
 NMR restraints: Bond =    0.000   Angle =     0.000   Torsion =     0.000
===============================================================================
 NSTEP =       10   TIME(PS) =       0.015  TEMP(K) =   229.60  PRESS =     0.0
 Etot   =     -2390.9966  EKtot   =       234.5205  EPtot      =     -2625.5170
 BOND   =        84.5193  ANGLE   =       153.2205  DIHED      =       292.3035
 1-4 NB =        93.9796  1-4 EEL =     -1596.0479  VDWAALS    =      -230.5382
 EELEC  =       991.2556  EGB     =     -2414.2094  RESTRAINT  =         0.0000
 ------------------------------------------------------------------------------
 NMR restraints: Bond =    0.000   Angle =     0.000   Torsion =     0.000
===============================================================================
 NSTEP =       20   TIME(PS) =       0.030  TEMP(K) =   281.06  PRESS =     0.0
 Etot   =     -2253.7608  EKtot   =       287.0774  EPtot      =     -2540.8382
 BOND   =        98.7574  ANGLE   =       203.1569  DIHED      =       297.2468
 1-4 NB =       100.5581  1-4 EEL =     -1599.6456  VDWAALS    =      -229.6152
 EELEC  =       998.2835  EGB     =     -2409.5801  RESTRAINT  =         0.0000
 ------------------------------------------------------------------------------
 NMR restraints: Bond =    0.000   Angle =     0.000   Torsion =     0.000
===============================================================================
 NSTEP =       30   TIME(PS) =       0.045  TEMP(K) =   296.69  PRESS =     0.0
 Etot   =     -2230.7932  EKtot   =       303.0465  EPtot      =     -2533.8397
 BOND   =       106.8442  ANGLE   =       196.3865  DIHED      =       302.9300
 1-4 NB =       102.3982  1-4 EEL =     -1602.0131  VDWAALS    =      -225.7046
 EELEC  =       986.5798  EGB     =     -2401.2606  RESTRAINT  =         0.0000
 ------------------------------------------------------------------------------
 NMR restraints: Bond =    0.000   Angle =     0.000   Torsion =     0.000
===============================================================================
 NSTEP =       40   TIME(PS) =       0.060  TEMP(K) =   285.59  PRESS =     0.0
 Etot   =     -2223.0507  EKtot   =       291.7026  EPtot      =     -2514.7533
 BOND   =       107.3846  ANGLE   =       206.2646  DIHED      =       306.5084
 1-4 NB =        94.2960  1-4 EEL =     -1588.1377  VDWAALS    =      -217.1324
 EELEC  =       980.1088  EGB     =     -2404.0455  RESTRAINT  =         0.0000
 ------------------------------------------------------------------------------
 NMR restraints: Bond =    0.000   Angle =     0.000   Torsion =     0.000
===============================================================================
 NSTEP =       50   TIME(PS) =       0.075  TEMP(K) =   304.90  PRESS =     0.0
 Etot   =     -2214.6613  EKtot   =       311.4273  EPtot      =     -2526.0886
 BOND   =       117.4039  ANGLE   =       194.1453  DIHED      =       305.2657
 1-4 NB =       101.3505  1-4 EEL =     -1610.1342  VDWAALS    =      -227.5490
 EELEC  =      1006.3729  EGB     =     -2412.9437  RESTRAINT  =         0.0000
 ------------------------------------------------------------------------------
 NMR restraints: Bond =    0.000   Angle =     0.000   Torsion =     0.000
===============================================================================
 NSTEP =       60   TIME(PS) =       0.090  TEMP(K) =   278.82  PRESS =     0.0
 Etot   =     -2233.4890  EKtot   =       284.7920  EPtot      =     -2518.2811
 BOND   =        97.3556  ANGLE   =       212.4408  DIHED      =       312.5412
 1-4 NB =       101.2733  1-4 EEL =     -1597.0333  VDWAALS    =      -228.1140
 EELEC  =       993.9940  EGB     =     -2410.7387  RESTRAINT  =         0.0000
 ------------------------------------------------------------------------------
 NMR restraints: Bond =    0.000   Angle =     0.000   Torsion =     0.000
===============================================================================
 NSTEP =       70   TIME(PS) =       0.105  TEMP(K) =   298.24  PRESS =     0.0
 Etot   =     -2219.1645  EKtot   =       304.6290  EPtot      =     -2523.7935
 BOND   =        98.8641  ANGLE   =       207.2412  DIHED      =       310.1483
 1-4 NB =        99.9853  1-4 EEL =     -1591.3145  VDWAALS    =      -231.2306
 EELEC  =       989.3254  EGB     =     -2406.8127  RESTRAINT  =         0.0000
 ------------------------------------------------------------------------------
 NMR restraints: Bond =    0.000   Angle =     0.000   Torsion =     0.000
===============================================================================
 NSTEP =       80   TIME(PS) =       0.120  TEMP(K) =   302.74  PRESS =     0.0
 Etot   =     -2219.9418  EKtot   =       309.2247  EPtot      =     -2529.1664
 BOND   =       114.6213  ANGLE   =       191.7638  DIHED      =       311.9104
 1-4 NB =        93.1754  1-4 EEL =     -1595.5519  VDWAALS    =      -226.1664
 EELEC  =       988.4763  EGB     =     -2407.3953  RESTRAINT  =         0.0000
 ------------------------------------------------------------------------------
 NMR restraints: Bond =    0.000   Angle =     0.000   Torsion =     0.000
===============================================================================
 NSTEP =       90   TIME(PS) =       0.135  TEMP(K) =   301.51  PRESS =     0.0
 Etot   =     -2196.3292  EKtot   =       307.9681  EPtot      =     -2504.2973
 BOND   =       108.0526  ANGLE   =       211.8796  DIHED      =       325.4895
 1-4 NB =       102.1647  1-4 EEL =     -1600.5646  VDWAALS    =      -228.9878
 EELEC  =       974.0873  EGB     =     -2396.4186  RESTRAINT  =         0.0000
 ------------------------------------------------------------------------------
 NMR restraints: Bond =    0.000   Angle =     0.000   Torsion =     0.000
===============================================================================
 NSTEP =      100   TIME(PS) =       0.150  TEMP(K) =   285.78  PRESS =     0.0
 Etot   =     -2209.3252  EKtot   =       291.8961  EPtot      =     -2501.2213
 BOND   =       114.9016  ANGLE   =       210.9523  DIHED      =       320.3746
 1-4 NB =        96.5399  1-4 EEL =     -1598.1488  VDWAALS    =      -223.0011
 EELEC  =       981.2488  EGB     =     -2404.0886  RESTRAINT  =         0.0000
 ------------------------------------------------------------------------------
 NMR restraints: Bond =    0.000   Angle =     0.000   Torsion =     0.000
===============================================================================
 NSTEP =      110   TIME(PS) =       0.165  TEMP(K) =   303.40  PRESS =     0.0
 Etot   =     -2220.6197  EKtot   =       309.8963  EPtot      =     -2530.5160
 BOND   =       106.4613  ANGLE   =       200.1546  DIHED      =       302.1341
 1-4 NB =       103.5301  1-4 EEL =     -1588.6475  VDWAALS    =      -228.9083
 EELEC  =       975.1808  EGB     =     -2400.4211  RESTRAINT  =         0.0000
 ------------------------------------------------------------------------------
 NMR restraints: Bond =    0.000   Angle =     0.000   Torsion =     0.000
===============================================================================
 NSTEP =      120   TIME(PS) =       0.180  TEMP(K) =   305.10  PRESS =     0.0
 Etot   =     -2201.7270  EKtot   =       311.6302  EPtot      =     -2513.3572
 BOND   =       104.4586  ANGLE   =       210.9078  DIHED      =       307.6163
 1-4 NB =       103.1315  1-4 EEL =     -1567.2926  VDWAALS    =      -224.8680
 EELEC  =       935.0566  EGB     =     -2382.3675  RESTRAINT  =         0.0000
 ------------------------------------------------------------------------------
*******************************************************************************
Pascal Baillod (PhD student) 
*******************************************************************************
Swiss Federal Institute of Technology EPFL	        Tel: +41-(0)21-693-0322
Institute of Chemical Sciences and Engineering ,	Fax: +41-(0)21-693-0320
Laboratory of Computational Chemistry and Biochemistry	pascal.baillod.epfl.ch
Room BCH 4121, Avenue Forel,	                        
http://lcbcpc21.epfl.ch
CH-1015 Lausanne	
*******************************************************************************
-----------------------------------------------------------------------
The AMBER Mail Reflector
To post, send mail to amber.scripps.edu
To unsubscribe, send "unsubscribe amber" to majordomo.scripps.edu
Received on Mon May 09 2005 - 17:53:00 PDT