[gmx-users] Dynamic updating of nstlist in gromacs 5 screws up simulation results

Szilárd Páll pall.szilard at gmail.com
Wed Jun 24 22:42:32 CEST 2015


Hi,

I think it is not very likely that the nstlist tuning would cause very
different results - especially not as a direct effect of the less
frequent pair search. With nstlist updated rlist also gets
recalculated; I've just checked and the estimates between 4.6 and 5.0
have not changed.

You can set nstlist on the command line (starting with v5.0) using the
"-nstlist" option, in v4.6 this is not exposed on the mdrun command
line interface, but it is supported through the GMX_NSTLIST
environment variable.

I suggest to try running v5.0 with -nstlist 10 and possibly also v4.6
with the increased nstlist=20.

Cheer,s
--
Szilárd


On Wed, Jun 24, 2015 at 7:53 PM, Michael Daily <mdaily.work at gmail.com> wrote:
> Hi,
>
> A colleague of mine and I have recently discovered that gromacs 4.6.4 and
> 5.0.4 give very different results in the simulation of a biomimetic polymer
> using an AMBER-based force field.  She found that gromacs 5 mdrun is
> dynamically changing nstlist from 10 to 20 or 40 depending on the
> simulation, as documented below.  Is it possible that this is causing the
> favored conformation of the polymer to change? Is there a way in GMX 5 to
> prevent this dynamic updating from happening?
>
> ### log file ###
> ++++ PLEASE READ AND CITE THE FOLLOWING REFERENCE ++++
> H. J. C. Berendsen, D. van der Spoel and R. van Drunen
> GROMACS: A message-passing parallel molecular dynamics implementation
> Comp. Phys. Comm. 91 (1995) pp. 43-56
> -------- -------- --- Thank You --- -------- --------
>
>
> NOTE: Error occurred during GPU detection:
>       CUDA driver version is insufficient for CUDA runtime version
>       Can not use GPU acceleration, will fall back to CPU kernels.
>
> Changing nstlist from 10 to 20, rlist from 1 to 1.029
>
> Input Parameters:
>    integrator                     = md
>    tinit                          = 0
>    dt                             = 0.002
>    nsteps                         = 100000000
>    init-step                      = 0
>    simulation-part                = 1
>    comm-mode                      = Linear
>    nstcomm                        = 100
>    bd-fric                        = 0
>    ld-seed                        = 2891701100
>    emtol                          = 10
>    emstep                         = 0.01
>    niter                          = 20
>    fcstep                         = 0
>    nstcgsteep                     = 1000
>    nbfgscorr                      = 10
>    rtpi                           = 0.05
>    nstxout                        = 5000
>    nstvout                        = 5000
>    nstfout                        = 5000
>    nstlog                         = 5000
>    nstcalcenergy                  = 100
>    nstenergy                      = 5000
>    nstxout-compressed             = 5000
>    compressed-x-precision         = 1000
>    cutoff-scheme                  = Verlet
>    nstlist                        = 20
>    ns-type                        = Grid
>    pbc                            = xyz
>    periodic-molecules             = FALSE
>    verlet-buffer-tolerance        = 0.005
>    rlist                          = 1.029
>    rlistlong                      = 1.029
>    nstcalclr                      = 10
>    coulombtype                    = PME
>    coulomb-modifier               = Potential-shift
>    rcoulomb-switch                = 0
>    rcoulomb                       = 1
>    epsilon-r                      = 1
>    epsilon-rf                     = inf
>    vdw-type                       = Cut-off
>    vdw-modifier                   = Potential-shift
>    rvdw-switch                    = 0
>    rvdw                           = 1
>    DispCorr                       = No
>    table-extension                = 1
>    fourierspacing                 = 0.12
>    fourier-nx                     = 52
>    fourier-ny                     = 52
>    fourier-nz                     = 52
>    pme-order                      = 4
>    ewald-rtol                     = 1e-05
>    ewald-rtol-lj                  = 0.001
>    lj-pme-comb-rule               = Geometric
>    ewald-geometry                 = 0
>    epsilon-surface                = 0
>    implicit-solvent               = No
>    gb-algorithm                   = Still
>    nstgbradii                     = 1
>    rgbradii                       = 1
>    gb-epsilon-solvent             = 80
>    gb-saltconc                    = 0
>    gb-obc-alpha                   = 1
>    gb-obc-beta                    = 0.8
>    gb-obc-gamma                   = 4.85
>    gb-dielectric-offset           = 0.009
>    sa-algorithm                   = Ace-approximation
>    sa-surface-tension             = 2.05016
>    tcoupl                         = Nose-Hoover
>    nsttcouple                     = 5
>    nh-chain-length                = 1
>    print-nose-hoover-chain-variables = FALSE
>    pcoupl                         = Parrinello-Rahman
>    pcoupltype                     = Isotropic
>    nstpcouple                     = 10
>    tau-p                          = 1
>    compressibility (3x3):
>       compressibility[    0]={ 4.50000e-05,  0.00000e+00,  0.00000e+00}
>       compressibility[    1]={ 0.00000e+00,  4.50000e-05,  0.00000e+00}
>       compressibility[    2]={ 0.00000e+00,  0.00000e+00,  4.50000e-05}
>    ref-p (3x3):
>       ref-p[    0]={ 1.00000e+00,  0.00000e+00,  0.00000e+00}
>       ref-p[    1]={ 0.00000e+00,  1.00000e+00,  0.00000e+00}
>       ref-p[    2]={ 0.00000e+00,  0.00000e+00,  1.00000e+00}
>    refcoord-scaling               = No
>    posres-com (3):
>       posres-com[0]= 0.00000e+00
>       posres-com[1]= 0.00000e+00
>       posres-com[2]= 0.00000e+00
>    posres-comB (3):
>       posres-comB[0]= 0.00000e+00
>       posres-comB[1]= 0.00000e+00
>       posres-comB[2]= 0.00000e+00
>    QMMM                           = FALSE
>    QMconstraints                  = 0
>    QMMMscheme                     = 0
>    MMChargeScaleFactor            = 1
> qm-opts:
>    ngQM                           = 0
>    constraint-algorithm           = Lincs
>    continuation                   = FALSE
>    Shake-SOR                      = FALSE
>    shake-tol                      = 0.0001
>    lincs-order                    = 4
>    lincs-iter                     = 1
>    lincs-warnangle                = 30
>    nwall                          = 0
>    wall-type                      = 9-3
>    wall-r-linpot                  = -1
>    wall-atomtype[0]               = -1
>    wall-atomtype[1]               = -1
>    wall-density[0]                = 0
>    wall-density[1]                = 0
>    wall-ewald-zfac                = 3
>    pull                           = no
>    rotation                       = FALSE
>    interactiveMD                  = FALSE
>    disre                          = No
>    disre-weighting                = Conservative
>    disre-mixed                    = FALSE
>    dr-fc                          = 1000
>    dr-tau                         = 0
>    nstdisreout                    = 100
>    orire-fc                       = 0
>    orire-tau                      = 0
>    nstorireout                    = 100
>    free-energy                    = no
>    cos-acceleration               = 0
>    deform (3x3):
>       deform[    0]={ 0.00000e+00,  0.00000e+00,  0.00000e+00}
>       deform[    1]={ 0.00000e+00,  0.00000e+00,  0.00000e+00}
>       deform[    2]={ 0.00000e+00,  0.00000e+00,  0.00000e+00}
>    simulated-tempering            = FALSE
>    E-x:
>       n = 0
>    E-xt:
>       n = 0
>    E-y:
>       n = 0
>    E-yt:
>       n = 0
>    E-z:
>       n = 0
>    E-zt:
>       n = 0
>    swapcoords                     = no
>    adress                         = FALSE
>    userint1                       = 0
>    userint2                       = 0
>    userint3                       = 0
>    userint4                       = 0
>    userreal1                      = 0
>    userreal2                      = 0
>    userreal3                      = 0
>    userreal4                      = 0
> grpopts:
>    nrdf:     291.972       31383     29.9972     29.9972
>    ref-t:         300         300         300         300
>    tau-t:         0.2         0.2         0.2         0.2
> annealing:          No          No          No          No
> annealing-npoints:           0           0           0           0
>    acc:           0           0           0
>    nfreeze:           N           N           N
>    energygrp-flags[  0]: 0
>
> Initializing Domain Decomposition on 24 ranks
> Dynamic load balancing: auto
> Will sort the charge groups at every domain (re)decomposition
> Initial maximum inter charge-group distances:
>     two-body bonded interactions: 0.425 nm, LJ-14, atoms 11 17
>   multi-body bonded interactions: 0.425 nm, Proper Dih., atoms 11 17
> Minimum cell size due to bonded interactions: 0.467 nm
> Maximum distance for 5 constraints, at 120 deg. angles, all-trans: 0.772 nm
> Estimated maximum distance required for P-LINCS: 0.772 nm
> This distance will limit the DD cell size, you can override this with -rcon
> Guess for relative PME load: 0.20
> Will use 18 particle-particle and 6 PME only ranks
> This is a guess, check the performance at the end of the log file
> Using 6 separate PME ranks, as guessed by mdrun
> Scaling the initial minimum size with 1/0.8 (option -dds) = 1.25
> Optimizing the DD grid for 18 cells with a minimum initial size of 0.965 nm
> The maximum allowed number of cells is: X 5 Y 5 Z 4
> Domain decomposition grid 3 x 2 x 3, separate PME ranks 6
> PME domain decomposition: 3 x 2 x 1
> Interleaving PP and PME ranks
> This rank does only particle-particle work.
>
> Domain decomposition rank 0, coordinates 0 0 0
>
> Using 24 MPI threads
> Using 1 OpenMP thread per tMPI thread
>
> Detecting CPU SIMD instructions.
> Present hardware specification:
> Vendor: GenuineIntel
> Brand:  Intel(R) Xeon(R) CPU           X5650  @ 2.67GHz
> Family:  6  Model: 44  Stepping:  2
> Features: aes apic clfsh cmov cx8 cx16 htt lahf_lm mmx msr nonstop_tsc pcid
> pclmuldq pdcm pdpe1gb popcnt pse rdtscp sse2 sse3 sse4.1 sse4.2 ssse3
> SIMD instructions most likely to fit this hardware: SSE4.1
> SIMD instructions selected at GROMACS compile time: SSE4.1
>
>
> No GPUs detected
>
> Will do PME sum in reciprocal space for electrostatic interactions.
>
> ++++ PLEASE READ AND CITE THE FOLLOWING REFERENCE ++++
> U. Essmann, L. Perera, M. L. Berkowitz, T. Darden, H. Lee and L. G.
> Pedersen
> A smooth particle mesh Ewald method
> J. Chem. Phys. 103 (1995) pp. 8577-8592
> -------- -------- --- Thank You --- -------- --------
>
> Will do ordinary reciprocal space Ewald sum.
> Using a Gaussian width (1/beta) of 0.320163 nm for Ewald
> Cut-off's:   NS: 1.029   Coulomb: 1   LJ: 1
> System total charge: 0.000
> Generated table with 1014 data points for Ewald.
> Tabscale = 500 points/nm
> Generated table with 1014 data points for LJ6.
> Tabscale = 500 points/nm
> Generated table with 1014 data points for LJ12.
> Tabscale = 500 points/nm
> Generated table with 1014 data points for 1-4 COUL.
> Tabscale = 500 points/nm
> Generated table with 1014 data points for 1-4 LJ6.
> Tabscale = 500 points/nm
> Generated table with 1014 data points for 1-4 LJ12.
> Tabscale = 500 points/nm
>
> Using SSE4.1 4x4 non-bonded kernels
>
> Using Lorentz-Berthelot Lennard-Jones combination rule
>
> Potential shift: LJ r^-12: -1.000e+00 r^-6: -1.000e+00, Ewald -1.000e-05
> Initialized non-bonded Ewald correction tables, spacing: 9.33e-04 size: 2176
>
> Removing pbc first time
> Pinning threads with an auto-selected logical core stride of 1
>
> Initializing Parallel LINear Constraint Solver
>
> ++++ PLEASE READ AND CITE THE FOLLOWING REFERENCE ++++
> B. Hess
> P-LINCS: A Parallel Linear Constraint Solver for molecular simulation
> J. Chem. Theory Comput. 4 (2008) pp. 116-122
> -------- -------- --- Thank You --- -------- --------
>
> The number of constraints is 152
> There are inter charge-group constraints,
> will communicate selected coordinates each lincs iteration
>
> ++++ PLEASE READ AND CITE THE FOLLOWING REFERENCE ++++
> S. Miyamoto and P. A. Kollman
> SETTLE: An Analytical Version of the SHAKE and RATTLE Algorithms for Rigid
> Water Models
> J. Comp. Chem. 13 (1992) pp. 952-962
> -------- -------- --- Thank You --- -------- --------
>
>
> Linking all bonded interactions to atoms
> There are 16397 inter charge-group exclusions,
> will use an extra communication step for exclusion forces for PME
>
> The initial number of communication pulses is: X 1 Y 1 Z 1
> The initial domain decomposition cell size is: X 1.66 nm Y 2.49 nm Z 1.44 nm
>
> The maximum allowed distance for charge groups involved in interactions is:
>                  non-bonded interactions           1.029 nm
> (the following are initial values, they could change due to box deformation)
>             two-body bonded interactions  (-rdd)   1.029 nm
>           multi-body bonded interactions  (-rdd)   1.029 nm
>   atoms separated by up to 5 constraints  (-rcon)  1.437 nm
>
> When dynamic load balancing gets turned on, these settings will change to:
> The maximum number of communication pulses is: X 1 Y 1 Z 1
> The minimum size for domain decomposition cells is 1.029 nm
> The requested allowed shrink of DD cells (option -dds) is: 0.80
> The allowed shrink of domain decomposition cells is: X 0.62 Y 0.41 Z 0.72
> The maximum allowed distance for charge groups involved in interactions is:
>                  non-bonded interactions           1.029 nm
>             two-body bonded interactions  (-rdd)   1.029 nm
>           multi-body bonded interactions  (-rdd)   1.029 nm
>   atoms separated by up to 5 constraints  (-rcon)  1.029 nm
>
>
> Making 3D domain decomposition grid 3 x 2 x 3, home cell index 0 0 0
>
> Center of mass motion removal mode is Linear
> We have the following groups for center of mass motion removal:
>   0:  rest
> There are: 15861 Atoms
> Charge group distribution at step 0: 853 904 881 863 893 859 857 913 880
> 866 892 881 893 888 889 884 888 877
>
> Constraining the starting coordinates (step 0)
>
> Constraining the coordinates at t0-dt (step 0)
> RMS relative constraint deviation after constraining: 0.00e+00
> Initial temperature: 299.753 K
>
> Started mdrun on rank 0 Wed Mar  4 19:25:32 2015
>            Step           Time         Lambda
>               0        0.00000        0.00000
>
>
> --
> ====================================
> Michael D. Daily
> Postdoctoral research associate
> Pacific Northwest National Lab (PNNL)
> 509-375-4581
> --
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