[gmx-developers] pressure calculation in GROMACS CVS

Mareike Zink mzink at gwdg.de
Thu May 15 10:21:05 CEST 2008


David: The mdp file I sent was for my subsystem. Here is the mdp file for the 
complete simulation system with more than 4 mil. atoms.

Berk: The temperature groups are 

Protein DAO ZN SOL_Na_Cl

Group 1: Protein, 762,300 atoms
Group 2: DAO: Fatty Acid, 2220 atoms
Group 3: Zinc, 12 atoms
Group 4: TIP4P water + Na + Cl ions: 3,451,758 atoms 

The pressure and volume values I sent you are from cvs version from April 15. 
Is there an even newer version? Then I can check (just needs some time 
because of the big system...) 


;
;	File 'mdout.mdp' was generated
;	By user: mzink (37571)
;	On host: beany
;	At date: Mon Mar 17 20:14:43 2008
;

; VARIOUS PREPROCESSING OPTIONS
title                    = 
; Preprocessor - specify a full path if necessary.
cpp                      = /lib/cpp
include                  = 
define                   = 

; RUN CONTROL PARAMETERS
integrator               = md
; Start time and timestep in ps
tinit                    = 0
dt                       = 0.002
nsteps                   = 5000
; For exact run continuation or redoing part of a run
init_step                = 0
; mode for center of mass motion removal
comm-mode                = Linear
; number of steps for center of mass motion removal
nstcomm                  = 1
; group(s) for center of mass motion removal
comm-grps                = 

; LANGEVIN DYNAMICS OPTIONS
; Friction coefficient (amu/ps) and random seed
bd-fric                  = 0
ld_seed                  = 1993

; ENERGY MINIMIZATION OPTIONS
; Force tolerance and initial step-size
emtol                    = 0.000001
emstep                   = 0.01
; Max number of iterations in relax_shells
niter                    = 100
; Step size (ps^2) for minimization of flexible constraints
fcstep                   = 0
; Frequency of steepest descents steps when doing CG
nstcgsteep               = 1000
nbfgscorr                = 10

; TEST PARTICLE INSERTION OPTIONS
rtpi                     = 0.05

; OUTPUT CONTROL OPTIONS
; Output frequency for coords (x), velocities (v) and forces (f)
nstxout                  = 5000
nstvout                  = 5000
nstfout                  = 5000
; Checkpointing helps you continue after crashes
nstcheckpoint            = 5000
; Output frequency for energies to log file and energy file
nstlog                   = 100
nstenergy                = 100
; Output frequency and precision for xtc file
nstxtcout                = 500
xtc_precision            = 1000
; This selects the subset of atoms for the xtc file. You can
; select multiple groups. By default all atoms will be written.
xtc-grps                 = Protein CA
; Selection of energy groups
energygrps               = Protein CA SOL

; NEIGHBORSEARCHING PARAMETERS
; nblist update frequency
nstlist                  = 10
; ns algorithm (simple or grid)
ns_type                  = grid
; Periodic boundary conditions: xyz, no, xy
pbc                      = xyz
periodic_molecules       = no
; nblist cut-off        
rlist                    = 0.9

; OPTIONS FOR ELECTROSTATICS AND VDW
; Method for doing electrostatics
coulombtype              = PME
rcoulomb_switch          = 0
rcoulomb                 = 0.9
; Relative dielectric constant for the medium and the reaction field
epsilon_r                = 1
epsilon_rf               = 1
; Method for doing Van der Waals
vdw-type                 = Cut-off
; cut-off lengths       
rvdw_switch              = 0
rvdw                     = 0.9
; Apply long range dispersion corrections for Energy and Pressure
DispCorr                 = No
; Extension of the potential lookup tables beyond the cut-off
table-extension          = 1
; Seperate tables between energy group pairs
energygrp_table          = 
; Spacing for the PME/PPPM FFT grid
;fourierspacing           = 0.12
; FFT grid size, when a value is 0 fourierspacing will be used
fourier_nx               = 120
fourier_ny               = 120
fourier_nz               = 120
; EWALD/PME/PPPM parameters
pme_order                = 4
ewald_rtol               = 1e-05
ewald_geometry           = 3d
epsilon_surface          = 0
optimize_fft             = no

; GENERALIZED BORN ELECTROSTATICS
; Algorithm for calculating Born radii
gb_algorithm             = Still
; Frequency of calculating the Born radii inside rlist
nstgbradii               = 1
; Cutoff for Born radii calculation; the contribution from atoms
; between rlist and rgbradii is updated every nstlist steps
rgbradii                 = 2
; Salt concentration in M for Generalized Born models
gb_saltconc              = 0

; IMPLICIT SOLVENT (for use with Generalized Born electrostatics)
implicit_solvent         = No

; OPTIONS FOR WEAK COUPLING ALGORITHMS
; Temperature coupling  
Tcoupl                   = berendsen
; Groups to couple separately
tc_grps                  = Protein Other
; Time constant (ps) and reference temperature (K)
tau_t                    = 0.1 0.1
ref_t                    = 300 300
; Pressure coupling     
Pcoupl                   = berendsen
Pcoupltype               = isotropic
; Time constant (ps), compressibility (1/bar) and reference P (bar)
tau_p                    = 1.0
compressibility          = 4.5e-5
ref_p                    = 1.0
; Scaling of reference coordinates, No, All or COM
refcoord_scaling         = No
; Random seed for Andersen thermostat
andersen_seed            = 815131

; OPTIONS FOR QMMM calculations
QMMM                     = no
; Groups treated Quantum Mechanically
QMMM-grps                = 
; QM method             
QMmethod                 = 
; QMMM scheme           
QMMMscheme               = normal
; QM basisset           
QMbasis                  = 
; QM charge             
QMcharge                 = 
; QM multiplicity       
QMmult                   = 
; Surface Hopping       
SH                       = 
; CAS space options     
CASorbitals              = 
CASelectrons             = 
SAon                     = 
SAoff                    = 
SAsteps                  = 
; Scale factor for MM charges
MMChargeScaleFactor      = 1
; Optimization of QM subsystem
bOPT                     = 
bTS                      = 

; SIMULATED ANNEALING  
; Type of annealing for each temperature group (no/single/periodic)
annealing                = no no
; Number of time points to use for specifying annealing in each group
annealing_npoints        = 
; List of times at the annealing points for each group
annealing_time           = 
; Temp. at each annealing point, for each group.
annealing_temp           = 

; GENERATE VELOCITIES FOR STARTUP RUN
gen_vel                  = yes
gen_temp                 = 300
gen_seed                 = 173529

; OPTIONS FOR BONDS    
constraints              = all-bonds
; Type of constraint algorithm
constraint-algorithm     = Lincs
; Do not constrain the start configuration
continuation             = yes
; Use successive overrelaxation to reduce the number of shake iterations
Shake-SOR                = no
; Relative tolerance of shake
shake_tol                = 1e-04
; Highest order in the expansion of the constraint coupling matrix
lincs-order              = 4
; Number of iterations in the final step of LINCS. 1 is fine for
; normal simulations, but use 2 to conserve energy in NVE runs.
; For energy minimization with constraints it should be 4 to 8.
lincs-iter               = 1
; Lincs will write a warning to the stderr if in one step a bond
; rotates over more degrees than
lincs-warnangle          = 30
; Convert harmonic bonds to morse potentials
morse                    = no

; ENERGY GROUP EXCLUSIONS
; Pairs of energy groups for which all non-bonded interactions are excluded
energygrp_excl           = 

; WALLS                
; Number of walls, type, atom types, densities and box-z scale factor for 
Ewald
nwall                    = 0
wall_type                = 9-3
wall_atomtype            = 
wall_density             = 
wall_ewald_zfac          = 3

; COM PULLING          
; Pull type: no, umbrella, constraint, constant_force
pull                     = no

; NMR refinement stuff 
; Distance restraints type: No, Simple or Ensemble
disre                    = No
; Force weighting of pairs in one distance restraint: Conservative or Equal
disre_weighting          = Equal
; Use sqrt of the time averaged times the instantaneous violation
disre_mixed              = no
disre_fc                 = 1000
disre_tau                = 1.25
; Output frequency for pair distances to energy file
nstdisreout              = 100
; Orientation restraints: No or Yes
orire                    = no
; Orientation restraints force constant and tau for time averaging
orire-fc                 = 0
orire-tau                = 0
orire-fitgrp             = 
; Output frequency for trace(SD) and S to energy file
nstorireout              = 100
; Dihedral angle restraints: No, Simple or Ensemble
dihre                    = No
dihre-fc                 = 1000
dihre-tau                = 0
; Output frequency for dihedral values to energy file
nstdihreout              = 100

; Free energy control stuff
free_energy              = no
init_lambda              = 0
delta_lambda             = 0
sc-alpha                 = 0
sc-power                 = 0
sc-sigma                 = 0.3

; Non-equilibrium MD stuff
acc-grps                 = 
accelerate               = 
freezegrps               = 
freezedim                = 
cos-acceleration         = 0
deform                   = 

; Electric fields      
; Format is number of terms (int) and for all terms an amplitude (real)
; and a phase angle (real)
E-x                      = 
E-xt                     = 
E-y                      = 
E-yt                     = 
E-z                      = 
E-zt                     = 

; User defined thingies
user1-grps               = 
user2-grps               = 
userint1                 = 0
userint2                 = 0
userint3                 = 0
userint4                 = 0
userreal1                = 0
userreal2                = 0
userreal3                = 0
userreal4                = 0





On Thursday 15 May 2008 10:01, you wrote:
> Mareike Zink wrote:
> > Hi,
> >
> > I did gmxcheck and there is only one difference in the temperature
> > groups, nrdf:
> >
> > gromacs 331.tpr
> >
> > grpopts:
> >       nrdf:	  1.5144e+06           0           0           0
> >       ref_t:	         300         300         300         300
> >       tau_t:	        0.01        0.01        0.01        0.01
> >
> > gromacs cvs.tpr
> >
> > grpopts:
> >       nrdf:	  1.5144e+06        4500          36  5.18155e+06
> >       ref_t:	         300         300         300         300
> >       tau_t:	        0.01        0.01        0.01        0.01
> >
> > All other options, coordinates, etc are completely identical.
> > Hope that helps,
> >
> > Mareike
>
> This helps indeed.
>
> You seem to have three temperature coupling groups with zero degrees of
> freedom.
> What are these groups?
>
> There seems to be a bug in the CVS version of grompp that you used,
> as the last group has 5 million degrees of freedom.
>
> Did you try the latest CVS version of grompp?
> If not, could you do so and gmxcheck with 331?
>
> Berk.



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