[gmx-users] Freezing problem

Dr. Vitaly Chaban vvchaban at gmail.com
Fri Nov 22 14:18:54 CET 2013


probably there should be three "freeze values" standing for Cartesions
directions. What I see below is "YYY" with no spaces between.


Dr. Vitaly V. Chaban


On Fri, Nov 22, 2013 at 1:56 PM, Debashis Sahu
<debashis.sahu87 at gmail.com> wrote:
> Dear all,
>            I can not freeze a group in mdrun in gas phase. Actually the
> following error is coming in the grompp step................
>
> Program grompp, VERSION 4.6.3
> Source code file: /compile/gromacs-4.6.3/src/kernel/readir.c, line: 3192
>
> Fatal error:
> Invalid Freezing input: 1 groups and 1 freeze values
> For more information and tips for troubleshooting, please check the GROMACS
> website at http://www.gromacs.org/Documentation/Errors
>
> I have tried also by taking the index file in grompp step, but same error
> coming. My index file and mdp file are listed below. I want to freeze ABC
> group while DDD will be free. In the topology I have inserted the molecule
> DDD as DDD.itp..........If any mistake in the files there, plz help me.
>
> *index.ndx file:*
>
> [ System ]
>    1    2    3    4    5    6    7    8    9   10   11   12   13   14   15
>   16   17   18   19   20   21   22   23   24   25   26   27   28   29   30
>   31   32   33   34   35   36   37   38   39   40   41   42   43   44   45
>   46   47   48   49   50   51   52   53   54   55   56   57   58   59   60
>   61   62   63   64   65   66   67   68   69   70   71   72   73   74   75
>   76   77   78   79   80   81   82   83   84   85   86   87   88   89   90
>   91   92   93   94   95   96   97   98   99  100  101  102  103  104  105
>  106  107  108  109  110  111  112  113  114  115  116  117  118  119  120
>  121  122  123  124  125  126  127  128  129
> [ Other ]
>    1    2    3    4    5    6    7    8    9   10   11   12   13   14   15
>   16   17   18   19   20   21   22   23   24   25   26   27   28   29   30
>   31   32   33   34   35   36   37   38   39   40   41   42   43   44   45
>   46   47   48   49   50   51   52   53   54   55   56   57   58   59   60
>   61   62   63   64   65   66   67   68   69   70   71   72   73   74   75
>   76   77   78   79   80   81   82   83   84   85   86   87   88   89   90
>   91   92   93   94   95   96   97   98   99  100  101  102  103  104  105
>  106  107  108  109  110  111  112  113  114  115  116  117  118  119  120
>  121  122  123  124  125  126  127  128  129
> [ ABC ]
>    1    2    3    4    5    6    7    8    9   10   11   12   13   14   15
>   16   17   18   19   20   21   22   23   24   25   26   27   28   29   30
>   31   32   33   34   35   36   37   38   39   40   41   42   43   44   45
>   46   47   48   49   50   51   52   53   54   55   56   57   58   59   60
>   61   62   63   64   65   66   67   68   69   70   71   72   73   74   75
>   76   77   78   79   80   81   82   83   84   85   86   87   88   89   90
>   91   92   93   94   95   96   97   98   99  100  101  102  103  104  105
>  106  107  108  109  110  111  112  113  114  115  116  117  118  119  120
>  121  122  123  124  125  126
> [ DDD ]
>  127  128  129
>
> *mdp file:*
>
> title = NVT equilibration
> define = -DPOSRES ; position restrain the solute
> ; Run parameters
> integrator = md ; leap-frog integrator
> nsteps = 50000 ; 2 * 50000 = 100 ps
> dt = 0.002 ; 2 fs
> ; Output control
> nstxout = 100 ; save coordinates every 0.2 ps
> nstvout = 100 ; save velocities every 0.2 ps
> nstenergy = 100 ; save energies every 0.2 ps
> nstlog = 100 ; update log file every 0.2 ps
> ; Bond parameters
> continuation = no ; first dynamics run
> constraint_algorithm = lincs ; holonomic constraints
> constraints = all-bonds ; all bonds (even heavy atom-H bonds) constrained
> lincs_iter = 1 ; accuracy of LINCS
> lincs_order = 4 ; also related to accuracy
> ; Neighborsearching
> ns_type = grid ; search neighboring grid cells
> nstlist = 5 ; 10 fs
> rlist = 1.0 ; short-range neighborlist cutoff (in nm)
> rcoulomb = 1.0 ; short-range electrostatic cutoff (in nm)
> rvdw = 1.0 ; short-range van der Waals cutoff (in nm)
> ; Electrostatics
> coulombtype = PME ; Particle Mesh Ewald for long-range electrostatics
> pme_order = 4 ; cubic interpolation
> fourierspacing = 0.16 ; grid spacing for FFT
> freezegrps = ABC
> freezedim =YYY
> ; Temperature coupling is on
> tcoupl = V-rescale ; modified Berendsen thermostat
> tc-grps = ABC  DDD ; two coupling groups - more accurate
> tau_t = 0.1 0.1 ; time constant, in ps
> ref_t = 300 300    ; reference temperature, one for each group, in K
> ; Pressure coupling is off
> pcoupl = no ; no pressure coupling in NVT
> ; Periodic boundary conditions
> pbc = xyz ; 3-D PBC
> ; Dispersion correction
> DispCorr = EnerPres ; account for cut-off vdW scheme
> ; Velocity generation
> gen_vel = yes ; assign velocities from Maxwell distribution
> gen_temp = 300 ; temperature for Maxwell distribution
> gen_seed = -1 ; generate a random seed
> --
> *Debashis Sahu*
> *Central Salt and Marine Chemical Research Institute*
> *Bhavnagar, Gujarat*
> *India, 364002.*
> --
> Gromacs Users mailing list
>
> * Please search the archive at http://www.gromacs.org/Support/Mailing_Lists/GMX-Users_List before posting!
>
> * Can't post? Read http://www.gromacs.org/Support/Mailing_Lists
>
> * For (un)subscribe requests visit
> https://maillist.sys.kth.se/mailman/listinfo/gromacs.org_gmx-users or send a mail to gmx-users-request at gromacs.org.


More information about the gromacs.org_gmx-users mailing list