[gmx-users] distance restraints and lincs warning

[A.Rampioni]

Dear colleagues,

I am performing some simulations on the following system: 
3 peptide in a beta-sheet configuration + other 3 peptides 
in a beta-sheet configuration 1 nm far apart in a 
truncated octahedron box.
I imposed on both the trimers improper dihedral restraints 
on one peptide and distance restraints among the peptides 
of the trimer.
I want to bring the two trimers close together, so I 
imposed some distance restraints even between the trimers.

I have performed an energy minimization of the starting 
configuration and a further mdrun with position restraints 
(without distance restraints) for  10 ps.

Then I turn on distance restraints and WITH THE VERSION 
3.1.4 EVERYTHING WORKS, BUT WITH THE VERSION 3.2.1 IT DOES 
NOT WORK !!!

Here I give you the distance restraints that I have used. 
When I use the first 8 dist.res. and just one of the last 
four (it doesn't matter which one, but just one!) it works 
for both the versions, otherwise only version 3.1.4 works.

[ distance_restraints ]
;  ai    aj    type    index    type    low    up1    up2 
   fac
    25   137     1        0       1      0.0    0.6    0.8 
   0.2
    73   185     1        1       1      0.0    0.6    0.8 
   0.2
   137   249     1        0       1      0.0    0.6    0.8 
   0.2
   185   297     1        1       1      0.0    0.6    0.8 
   0.2
   361   473     1        0       1      0.0    0.6    0.8 
   0.2
   409   521     1        1       1      0.0    0.6    0.8 
   0.2
   473   585     1        0       1      0.0    0.6    0.8 
   0.2
   521   633     1        1       1      0.0    0.6    0.8 
   0.2
    25   424     1        2       1      0.0    0.6    0.8 
   0.2
    73   379     1        3       1      0.0    0.6    0.8 
   0.2
   249   648     1        2       1      0.0    0.6    0.8 
   0.2
   297   603     1        3       1      0.0    0.6    0.8 
   0.2

Here I list the options about dist. res. that I have used

disre                    = simple
disre_weighting          = equal
disre_mixed              = no
disre_fc                 = 1000
disre_tau                = 0
nstdisreout              = 100


Here it is the MESSAGE ERROR:

Step 0, time 0 (ps)  LINCS WARNING
relative constraint deviation after LINCS:
max 183.362411 (between atoms 444 and 445) rms 23.975990
bonds that rotated more than 30 degrees:
  atom 1 atom 2  angle  previous, current, constraint 
length
     415    416  110.7    0.1471   0.1564      0.1470
     416    417  114.1    0.1526   0.1499      0.1530
     416    420   49.9    0.1530   0.5337      0.1530
     417    418   35.6    0.1531   0.1890      0.1530
     420    422  109.8    0.1327   5.3983      0.1330
     422    424  178.6   10.1607  12.4716      0.1470
     424    425  175.0   10.2412  12.6243      0.1530
     424    438  178.1   10.3766  13.3002      0.1530
   


Any idea of what can be wrong?

Thanks

Aldo