Hello, Victor!

Is it possible do not use tables_*.xvg and instead of it set the
parameters for bond, angle and dihedral to the topol.top with
equilibrium bond length, angle and force constants. In this case ibi-
procedure for my system works.
And how one can choose the exact simulation time for one iteration for
different systems?

Thanks a lot in advance,
Sergio

On Jul 5, 5:04 pm, Victor Ruehle <[email protected]> wrote:
> Hey,
>
> 1) I recommend to use version 1.2. The functionality + arguments of
> convert_potentials have slightly changed.
>
> 2) in the files you sent me, the bad sampled regions were not cut and
> therefore the extrapolate failed (zoom in at table_a0.xvg where the
> extrapolated region at the left starts). This will lead to a very
> strong peak in the force and is probably what messes up your run.
> Please make sure to really cut the very rough points at the left and
> right of bonded potentials. This was done in the sed commands i send
> you. Either adjust the number of points there or better skip this
> command and do it manually.
>
> Victor
>
> 2011/7/5 chemistry <[email protected]>:
>
> > Hey,
>
> > the format of the table_*.xvg which was created after post-processing
> > looks like this:
>
> > table_a1.xvg:
>
> > 0.0000000000e+00   8.6955642509e+07 0.0000000000e+00
> > 5.0000000000e-02   8.6862417509e+07 1.8640000000e+06
> > 1.0000000000e-01   8.6769242509e+07 1.8630000000e+06
> > 1.5000000000e-01   8.6676117509e+07 1.8620000000e+06
> > 2.0000000000e-01   8.6583042509e+07 1.8610000000e+06
>
> > and yesterday I've created the same format of the table like in your
> > case by myself. I used for this C-programing and described the
> > potential with the help of harmonic potential. And now it works well.
>
> > new one table_a1.xvg:
>
> > 0.000000 1201.461834 0
> > 0.050000 1200.343519 0
> > 0.100000 1199.225724 0
> > 0.150000 1198.108451 0
> > 0.200000 1196.991698 0
>
> > In both cases the potentials look similar around the minimum. Is it
> > possible that the GROMACS in someway cannot read correctly the
> > table_*.xvg?
>
> > Kind regards,
> > Sergio
>
> > On Jul 4, 7:50 pm, Victor Ruehle <[email protected]> wrote:
> >> Hey,
>
> >> can you please attach your table_?.xvg
>
> >> Cheers,
> >> Victor
>
> >> 2011/7/4 chemistry <[email protected]>:
>
> >> > Hey, Victor!
>
> >> > With table_b1.xvg and table_a1.xvg from your tutorial simulation for
> >> > propane works well.
> >> > I'd tried to process the potentials for propane myself and after when
> >> > I started the simulations I've got the same mistake like for my
> >> > system:
>
> >> > "Fatal error:
> >> > A tabulated bond interaction table number 1 is out of the table range:
> >> > r 3.157974, between table indices 3157 and 3158, table length 501"
>
> >> > Seems that I have some problem with creating the tables_*.xvg
> >> > Can you please check the way of post-processing of the potentials.
> >> > At the beginning I had the same shape of the potential like in your
> >> > case (I've got it with csg_boltzmann from all-atom MD simulation of
> >> > propane at T=200 K):
>
> >> > bond:
>
> >> > sed -e '1,5d' -e 's/$/ i/' AB.pot | tac | sed -e '1,4d' | tac > AB.cut
> >> > csg_call table smooth AB.cut AB.smooth
> >> > csg_resample --in AB.smooth --out AB.refined --grid 0::0.001:0.5
> >> > csg_call table extrapolate --function quadratic AB.refined AB.pot.cur
> >> > csg_call --options table.xml convert_potential xvg --type bonded
> >> > AB.pot.cur table_b1.xvg
>
> >> > where table.xml:
>
> >> > <cg>
> >> >   <inverse>
> >> >    <gromacs>
> >> >     <pot_max>1e8</pot_max>
> >> >     <table_end>0.5</table_end>
> >> >     <table_bins>0.002</table_bins>
> >> >    </gromacs>
> >> >   </inverse>
> >> > </cg>
>
> >> > angle:
>
> >> > sed -e 's/$/ i/' ABA_angle.pot | tac | sed -e '1,2d' | tac  > ABA.cut
> >> > awk '{print $1/3.141592654*180.0,$2,$3,$4}' ABA.cut > ABA.new.cut
> >> > csg_call table smooth ABA.new.cut ABA.smooth
> >> > csg_resample --in ABA.smooth --out ABA.refined --grid 0::0.05:180
> >> > csg_call table extrapolate --function quadratic ABA.refined
> >> > ABA.pot.cur
> >> > csg_call --options table.xml convert_potential xvg --type bonded
> >> > ABA.pot.cur table_a1.xvg
>
> >> > where table.xml:
>
> >> > <cg>
> >> >   <inverse>
> >> >    <gromacs>
> >> >     <pot_max>1e8</pot_max>
> >> >     <table_end>180</table_end>
> >> >     <table_bins>0.05</table_bins>
> >> >    </gromacs>
> >> >   </inverse>
> >> > </cg>
>
> >> > In both cases the potentials look similar around the minimum, but
> >> > afterwords they are totally different. I wanted to get the same
> >> > table_*.xvg like in your example.
>
> >> > Yours respectfully,
> >> > Sergio
>
> >> > On Jul 1, 11:34 am, Victor Ruehle <[email protected]> wrote:
> >> >> Be aware, if you have a bug in your coarse-grained topology, it might
> >> >> immediately crash the simulations similar to the problem you
> >> >> described. The csg_map will give a reasonable initial structure, this
> >> >> should do well if your coarse-grained potentials are ok (eventually do
> >> >> a steep before). The topology generation (csg_gmxtopol) just provides
> >> >> a point to start from but will always require tuning by hand to put in
> >> >> correct parameters.
>
> >> >> Also verify your mapping by loading atomistic + coarse-grained
> >> >> structures in vmd.
>
> >> >> 2011/7/1 chemistry <[email protected]>:
>
> >> >> > Sorry, it was a problem with the internet and that's why I posted the
> >> >> > same message twice.
>
> >> >> > I'm doing it in the same way how you wrote. So, I'll check all stuff
> >> >> > again and thanks for fast answer.
>
> >> >> > Kind regards.
>
> >> >> > On Jul 1, 11:14 am, chemistry <[email protected]> wrote:
> >> >> >> Hello!
>
> >> >> >> Seems that I have not a good initial CG-structure. I've got it with
> >> >> >> the help of csg_map:
>
> >> >> >> $csg_map --top topol.tpr --trj traj.trr --cg mappin.xml --out cg.gro
>
> >> >> >> In my mappin.xml file every monomer of my system (P3HT) divided on 
> >> >> >> the
> >> >> >> three beads and each bead has a different name.
> >> >> >> How exactly did you get initial CG-structure for propene in your
> >> >> >> example?
>
> >> >> >> Thanks a lot in advance,
> >> >> >> Sergio
>
> >> >> >> On Jun 30, 12:20 pm, Sebastian <[email protected]> wrote:
>
> >> >> >> > Hi 'chemistry',
>
> >> >> >> > it seems your bond is streching to far, this could be due to a too
> >> >> >> > weak minimum in the bonded interaction or beacause your system
> >> >> >> > explodes (too high energies) in some other part of the system.
> >> >> >> > I would try:
> >> >> >> > 1) run a steepest decent before the actual simulation
> >> >> >> > 2) make the bonded table longer by filling up some zeroes. Then 
> >> >> >> > check
> >> >> >> > if something else breaks (with a 'out of range') error....
>
> >> >> >> > -Sebastian
>
> >> >> >> > On Jun 30, 10:34 am, chemistry <[email protected]> wrote:
>
> >> >> >> > > Hello!
>
> >> >> >> > > Thanks again for advices. It's helped me a lot.
> >> >> >> > > I have already created all files what I need for CG calculation. 
> >> >> >> > > But
> >> >> >> > > now I have a problem with a tabulated bond interaction. I've 
> >> >> >> > > checked
> >> >> >> > > already this problem on the gromacs mailing-list. Unfortunately 
> >> >> >> > > they
> >> >> >> > > do not have any good advice there how to solve this problem. I 
> >> >> >> > > would
> >> >> >> > > be very grateful if you can give me some advice how to solve it. 
> >> >> >> > > I
> >> >> >> > > have next error message:
>
> >> >> >> > > "Fatal error:
> >> >> >> > > A tabulated bond interaction table number 2 is out of the table 
> >> >> >> > > range:
> >> >> >> > > r 0.646802, between table indices 646 and 647, table length 501"
>
> >> >> >> > > Thanks a lot in advance,
> >> >> >> > > Sergio.
>
> >> >> >> > > On Jun 27, 6:33 pm, Victor Ruehle <[email protected]> wrote:
>
> >> >> >> > > > Hey,
>
> >> >> >> > > > i also use csg_boltzmann, the tab command (dont forget tab set 
> >> >> >> > > > scale
> >> >> >> > > > bond / tab set scale angle for bond/angles). some of my 
> >> >> >> > > > examples (the
> >> >> >> > > > .pot files are the output of csg_boltzmann):
> >> >> >> > > > bonds:
> >> >> >> > > > cp ../../pot/AB_bond.pot .
> >> >> >> > > > sed -e '1,5d' -e 's/$/ i/' AB_bond.pot | tac | sed -e '1,4d' | 
> >> >> >> > > > tac >
> >> >> >> > > > AB.cut   ; cut bad sampled regions at the boundaries
> >> >> >> > > > csg_call table smooth AB.cut AB.smooth
> >> >> >> > > > csg_resample --in AB.smooth --out AB.refined --grid 
> >> >> >> > > > 0::0.001:0.5
> >> >> >> > > > csg_call table extrapolate --function quadratic AB.refined 
> >> >> >> > > > AB.pot.cur
> >> >> >> > > > csg_call --ia-type bonded --ia-name AB --options ../convert.xml
> >> >> >> > > > convert_potential gromacs
>
> >> >> >> > > > angles:
> >> >> >> > > > cp ../../pot/ABC_angle.pot .
> >> >> >> > > > #sed -e '1,3d' -e 's/$/ i/' ABC_angle.pot | tac | sed -e 
> >> >> >> > > > '1,3d' | tac > ABC.cut
> >> >> >> > > > sed -e 's/$/ i/' ABC_angle.pot | tac | sed -e '1,2d' | tac  > 
> >> >> >> > > > ABC.cut
> >> >> >> > > > csg_call table smooth ABC.cut ABC.smooth
> >> >> >> > > > csg_resample --in ABC.smooth --out ABC.refined --grid 
> >> >> >> > > > 0::0.001:3.141592654
> >> >> >> > > > csg_call table extrapolate --function quadratic --region left
> >> >> >> > > > ABC.refined ABC.refined
> >> >> >> > > > csg_call table extrapolate --function linear --region right
> >> >> >> > > > ABC.refined ABC.refined
> >> >> >> > > > awk '{print $1/3.141592654*180.0,$2}' ABC.refined > ABC.pot.cur
> >> >> >> > > > csg_call --ia-type angle --ia-name ABC --options ../convert.xml
> >> >> >> > > > convert_potential gromacs
>
> >> >> >> > > > convert.xml:
> >> >> >> > > > <cg>
> >> >> >> > > >   <bonded>
> >> >> >> > > >     <name>AB</name>
> >> >> >> > > >     <inverse>
> >> >> >> > > >       <gromacs>
> >> >> >> > > >         <table>../tables/table_b0.xvg</table>
> >> >> >> > > >       </gromacs>
> >> >> >> > > >     </inverse>
> >> >> >> > > >   </bonded>
> >> >> >> > > >   <bonded>
> >> >> >> > > >     <name>BC</name>
> >> >> >> > > >     <inverse>
> >> >> >> > > >       <gromacs>
> >> >> >> > > >         <table>../tables/table_b1.xvg</table>
> >> >> >> > > >       </gromacs>
> >> >> >> > > >     </inverse>
> >> >> >> > > >   </bonded>
> >> >> >> > > >   <angle>
> >> >> >> > > >     <name>ABC</name>
> >> >> >> > > >     <inverse>
> >> >> >> > > >       <gromacs>
> >> >> >> > > >         <table>../tables/table_a0.xvg</table>
> >> >> >> > > >       </gromacs>
> >> >> >> > > >     </inverse>
> >> >> >> > > >   </angle>
>
> >> >> >> > > >   <inverse>
> >> >> >> > > >     <gromacs>
> >> >> >> > > >       <table_end>3.0</table_end>
> >> >> >> > > >       <table_bins>0.002</table_bins>
> >> >> >> > > >       <pot_max>1000000</pot_max>
> >> >> >> > > >     </gromacs>
>
> ...
>
> read more »

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