[gmx-users] Domain decomposition error in alchemical free energy perturbation MD

lina lina.lastname at gmail.com
Sat Oct 15 13:22:04 CEST 2011


On Sat, Oct 15, 2011 at 2:11 PM, Xiaoxiao He <xxiaohe at ust.hk> wrote:
> Dear all,
> I'm doing an "slow-growth" alchemical free energy perturbation calculation
> of the formation of a disulfide bridge between two Cysteines with Gromacs.
> I've had tried different ways to combine the topology of both state A and
> state B, and finally settled with the most direct way -- to "mutate" the
> atoms that have different partial charges in the two states, and transform
> the two hydrogen atoms into "dummy" atoms. As suggested by Gromacs manual
> and some messages from the internet, I put explicitly the OPLS parameters
> for the bonds, pairs, angles and dihedrals changed from state A to state B,
> and the grompp didn't give a warning. But when I was testing the production
> simulation on two processors, there was a warning of fatal error in the log
> file:
> =========================================================================================
> Initializing Domain Decomposition on 2 nodes
> Dynamic load balancing: auto
> Will sort the charge groups at every domain (re)decomposition
> Initial maximum inter charge-group distances:
>     two-body bonded interactions: 3.774 nm, LJC Pairs NB, atoms 12 205
>   multi-body bonded interactions: 0.640 nm, Ryckaert-Bell., atoms 1013 417
> Minimum cell size due to bonded interactions: 4.151 nm
> Using 0 separate PME nodes
> Scaling the initial minimum size with 1/0.8 (option -dds) = 1.25
> Optimizing the DD grid for 2 cells with a minimum initial size of 5.189 nm
> The maximum allowed number of cells is: X 0 Y 0 Z 0
> -------------------------------------------------------
> Program mdrun, VERSION 4.5.4
> Source code file: domdec.c, line: 6436
> Fatal error:
> There is no domain decomposition for 2 nodes that is compatible with the
> given box and a minimum cell size of 5.18876 nm
> Change the number of nodes or mdrun option -rdd or -dds

as suggested by the log:

1] Change the number of nodes
or
2] mdrun option -rdd or -dds



> Look in the log file for details on the domain decomposition
> For more information and tips for troubleshooting, please check the GROMACS
> website at http://www.gromacs.org/Documentation/Errors
> =============================================================================================
> The atoms indexed 12 and 205 are a CD1 in Leu1 and another CB in Ala12
> respectively. I checked the topology and found no entries containing both
> these atoms. What's weird is that there's no way for these two atoms to have
> bonded interactions, but it says in the log that they have a two-body bonded
> interaction with a distance of 3.774 nm, which I cannot understand.
> Does anyone have an explanation what this could mean? Any suggestion is
> appreciated!
> Thanks in advance!
>
> Xiaoxiao He
> Oct. 15, 2011
>
>
> Attached are the input  parameters for the production md:
> =====================================================================
> -Input Parameters:
>    integrator           = sd
>    nsteps               = 2000000
>    init_step            = 0
>    ns_type              = Grid
>    nstlist              = 10
>    ndelta               = 2
>    nstcomm              = 10
>    comm_mode            = Linear
>    nstlog               = 100
>    nstxout              = 100000
>    nstvout              = 100000
>    nstfout              = 100000
>    nstcalcenergy        = 10
>    nstenergy            = 100
>    nstxtcout            = 1000
>    init_t               = 0
>    delta_t              = 0.0005
>    xtcprec              = 1000
>    nkx                  = 36
>    nky                  = 36
>    nkz                  = 36
>    pme_order            = 4
>    ewald_rtol           = 1e-05
>    ewald_geometry       = 0
>    epsilon_surface      = 0
>    optimize_fft         = TRUE
>    ePBC                 = xyz
>    bPeriodicMols        = FALSE
>    bContinuation        = FALSE
>    bShakeSOR            = FALSE
>    etc                  = No
>    nsttcouple           = -1
>    epc                  = Berendsen
>    epctype              = Isotropic
>    nstpcouple           = 10
>    tau_p                = 1
>    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}
>    compress (3x3):
>       compress[    0]={ 4.50000e-05,  0.00000e+00,  0.00000e+00}
>       compress[    1]={ 0.00000e+00,  4.50000e-05,  0.00000e+00}
>       compress[    2]={ 0.00000e+00,  0.00000e+00,  4.50000e-05}
>    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
>    andersen_seed        = 815131
>    rlist                = 1.3
>    rlistlong            = 1.3
>    rtpi                 = 0.05
>    coulombtype          = PME
>    rcoulomb_switch      = 0
>    rcoulomb             = 1.3
>    vdwtype              = Switch
>    rvdw_switch          = 0.8
>    rvdw                 = 0.9
>    epsilon_r            = 1
>    epsilon_rf           = 1
>    tabext               = 1
>    implicit_solvent     = No
>    gb_algorithm         = Still
>    gb_epsilon_solvent   = 80
>    nstgbradii           = 1
>    rgbradii             = 1
>    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
>    DispCorr             = EnerPres
>    free_energy          = yes
>    init_lambda          = 0
>    delta_lambda         = 5e-07
>    n_foreign_lambda     = 0
>    sc_alpha             = 0.5
>    sc_power             = 1
>    sc_sigma             = 0.3
>    sc_sigma_min         = 0.3
>    nstdhdl              = 10
>    separate_dhdl_file   = no
>    dhdl_derivatives     = yes
>    dh_hist_size         = 0
>    dh_hist_spacing      = 0.1
>    nwall                = 0
>    wall_type            = 9-3
>    wall_atomtype[0]     = -1
>    wall_atomtype[1]     = -1
>    wall_density[0]      = 0
>    wall_density[1]      = 0
>    wall_ewald_zfac      = 3
>    pull                 = no
>    disre                = No
>    disre_weighting      = Conservative
>    disre_mixed          = FALSE
>    dr_fc                = 1000
>    dr_tau               = 0
>    nstdisreout          = 100
>    orires_fc            = 0
>    orires_tau           = 0
>    nstorireout          = 100
>    dihre-fc             = 1000
>    em_stepsize          = 0.01
>    em_tol               = 10
>    niter                = 20
>    fc_stepsize          = 0
>    nstcgsteep           = 1000
>    nbfgscorr            = 10
>    ConstAlg             = Lincs
>    shake_tol            = 0.0001
>    lincs_order          = 4
>    lincs_warnangle      = 30
>    lincs_iter           = 1
>    bd_fric              = 0
>    ld_seed              = 1993
>    cos_accel            = 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}
>    userint1             = 0
>    userint2             = 0
>    userint3             = 0
>    userint4             = 0
>    userreal1            = 0
>    userreal2            = 0
>    userreal3            = 0
>    userreal4            = 0
> grpopts:
>    nrdf:        3903       22866
>    ref_t:         300         300
>    tau_t:         0.1         0.1
> anneal:          No          No
> ann_npoints:           0           0
>    acc:           0           0           0
>    nfreeze:           N           N           N
>    energygrp_flags[  0]: 0
>    efield-x:
>       n = 0
>    efield-xt:
>       n = 0
>    efield-y:
>       n = 0
>    efield-yt:
>       n = 0
>    efield-z:
>       n = 0
>    efield-zt:
>       n = 0
>    bQMMM                = FALSE
>    QMconstraints        = 0
>    QMMMscheme           = 0
>    scalefactor          = 1
> qm_opts:
>    ngQM                 = 0
> ======================================================================================================
>
> --
> Xiaoxiao HE
> Department of Chemistry
> The Hong Kong University of Science and Technology
> Clear Water Bay, Kowloon
> Hong Kong
> Email: xxiaohe at ust.hk     Tel: 23585896
>
> --
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