[gmx-users] Re: Regarding Na ions

naga raju nagaraju_cy at yahoo.co.in
Fri Jul 6 06:50:38 CEST 2007


Dear gmx users,
          I am thankful to Dr.Mark and Dr.Osmair for
their responce to my queries. As per their suggestion,
I checked ions.itp file in that sodium atoms are
represented by NA+ in opls force field. I am using
gromacs 3.3.1 version.

[moleculetype ]
; molname	nrexcl
NA+		1

[ atoms ]
; id	at type		res nr 	residu name	at name  cg nr
charge   mass
1	opls_407	1	NA+	NA	1	1	22.98977	

As per Dr.Osmair suggestion, I built a sodium.itp
file, the file was shown below.

ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ
[ moleculetype ]
; NAme            nrexcl
NA+                1

[ atoms ]
;   nr       type  resnr residue  atom   cgnr    
charge       mass  typeB    chargeB      massB
     1   opls_407      1    NA+     NA      1         
1    22.9898   ; qtot 1
     2   opls_407      2    NA+     NA      2         
1    22.9898   ; qtot 2
     3   opls_407      3    NA+     NA      3         
1    22.9898   ; qtot 3
     4   opls_407      4    NA+     NA      4         
1    22.9898   ; qtot 4
     5   opls_407      5    NA+     NA      5         
1    22.9898   ; qtot 5
     6   opls_407      6    NA+     NA      6         
1    22.9898   ; qtot 6
     7   opls_407      7    NA+     NA      7         
1    22.9898   ; qtot 7
     8   opls_407      8    NA+     NA      8         
1    22.9898   ; qtot 8
     9   opls_407      9    NA+     NA      9         
1    22.9898   ; qtot 9
    10   opls_407     10    NA+     NA     10         
1    22.9898   ; qtot 10
    11   opls_407     11    NA+     NA     11         
1    22.9898   ; qtot 11
    12   opls_407     12    NA+     NA     12         
1    22.9898   ; qtot 12
    .........
    ..........
    ..........

    and also tried with the fallowing type...

[ moleculetype ]
; Name            nrexcl
Sodium                1

[ atoms ]
;   nr       type  resnr residue  atom   cgnr    
charge       mass  typeB    chargeB      massB
     1   opls_405      1    Na     Na      1         
1    35.4530   ; qtot 1
     2   opls_405      2    Na     Na      2         
1    35.4530   ; qtot 2
     3   opls_405      3    Na     Na      3         
1    35.4530   ; qtot 3
     4   opls_405      4    Na     Na      4         
1    35.4530   ; qtot 4
     5   opls_405      5    Na     Na      5         
1    35.4530   ; qtot 5
     6   opls_405      6    Na     Na      6         
1    35.4530   ; qtot 6
     7   opls_405      7    Na     Na      7         
1    35.4530   ; qtot 7
     8   opls_405      8    Na     Na      8         
1    35.4530   ; qtot 8
     9   opls_405      9    Na     Na      9         
1    35.4530   ; qtot 9
     .............
     .............
     .............
ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ

When i run grompp command to prepare bilater-ions.tpr
file, I couldn't observe any error message and shown
below.

xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
processing topology...
Generated 345696 of the 345696 non-bonded parameter
combinations
Generating 1-4 interactions: fudge = 0.5
Generated 345606 of the 345696 1-4 parameter
combinations
Excluding 3 bonded neighbours for POPE 96
turning all bonds into constraints...
Excluding 3 bonded neighbours for DPOP 32
turning all bonds into constraints...
Excluding 2 bonded neighbours for SOL 3909
turning all bonds into constraints...
Excluding 1 bonded neighbours for NA+ 1
turning all bonds into constraints...
processing coordinates...
double-checking input for internal consistency...
Velocities were taken from a Maxwell distribution at
303 K
renumbering atomtypes...
converting bonded parameters...
#     ANGLES:   7520
#      PDIHS:   3424
#     RBDIHS:   2944
#      IDIHS:   544
#       LJ14:   3680
#     CONSTR:   6560
#     SETTLE:   3909
Walking down the molecule graph to make shake-blocks
initialising group options...
processing index file...
Making dummy/rest group for Acceleration containing
18447 elements
Making dummy/rest group for Freeze containing 18447
elements
Making dummy/rest group for Energy Mon. containing
18447 elements
Making dummy/rest group for VCM containing 18447
elements
Number of degrees of freedom in T-Coupling group POP
is 10079.18
Number of degrees of freedom in T-Coupling group DPO
is 3423.72
Number of degrees of freedom in T-Coupling group SOL
is 23452.10
Number of degrees of freedom in T-Coupling group NA+
is 95.99
Making dummy/rest group for User1 containing 18447
elements
Making dummy/rest group for User2 containing 18447
elements
Making dummy/rest group for XTC containing 18447
elements
Making dummy/rest group for Or. Res. Fit containing
18447 elements
Making dummy/rest group for QMMM containing 18447
elements
T-Coupling       has 4 element(s): POP DPO SOL NA+
Energy Mon.      has 1 element(s): rest
Acceleration     has 1 element(s): rest
Freeze           has 1 element(s): rest
User1            has 1 element(s): rest
User2            has 1 element(s): rest
VCM              has 1 element(s): rest
XTC              has 1 element(s): rest
Or. Res. Fit     has 1 element(s): rest
QMMM             has 1 element(s): rest
Checking consistency between energy and charge
groups...
Calculating fourier grid dimensions for X Y Z
Using a fourier grid of 65x65x70, spacing 0.119 0.119
0.117
writing run input file...
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

When I am runing mdrun command, I got the fallowing
error messages and after some time segmentation fault.

zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz

Step 32, time 0.064 (ps)  LINCS WARNING
relative constraint deviation after LINCS:
max 0.002582 (between atoms 5262 and 5310) rms
0.000038
bonds that rotated more than 30 degrees:
 atom 1 atom 2  angle  previous, current, constraint
length
   5262   5310   31.2    0.1000   0.0997      0.1000
 
Step 33, time 0.066 (ps)  LINCS WARNING
relative constraint deviation after LINCS:
max 0.003343 (between atoms 5262 and 5310) rms
0.000057
bonds that rotated more than 30 degrees:
 atom 1 atom 2  angle  previous, current, constraint
length
   5368   5416   69.4    0.0999   0.1001      0.1000
 
Step 34, time 0.068 (ps)  LINCS WARNING
relative constraint deviation after LINCS:
max 0.005428 (between atoms 5262 and 5310) rms
0.000076
bonds that rotated more than 30 degrees:
 atom 1 atom 2  angle  previous, current, constraint
length
   5262   5310   67.9    0.1003   0.0995      0.1000
   5368   5416   47.0    0.1001   0.1002      0.1000
 
Step 35, time 0.07 (ps)  LINCS WARNING
relative constraint deviation after LINCS:
max 0.002371 (between atoms 5368 and 5416) rms
0.000036
bonds that rotated more than 30 degrees:
 atom 1 atom 2  angle  previous, current, constraint
length
   5262   5310   43.4    0.0995   0.1002      0.1000
   5368   5416   40.9    0.1002   0.0998      0.1000
zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz

Can you tell where I have done mistake.
Any suggestion is appreciated.

                  Thank you in advance.
                                   with best regards,
                                      Nagaraju



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