Re: [AMBER] generalized distance restraint

From: Carlos Simmerling <carlos.simmerling.gmail.com>
Date: Mon, 9 Mar 2009 12:39:43 -0400

well I can't say much about the jar option, but in your case you
didn't write an end to the first restraint so sander probably thinks
there is only 1. maybe someone else can say whether jar with >1
restraint will work.



On Mon, Mar 9, 2009 at 12:15 PM, Rausch, Felix <frausch.ipb-halle.de> wrote:
> Thank you for your fast reply.
> Im sorry that my first mail wasnt accurate enough.
>
> Until now, i started all my Steered MDs with Amber10 for free energy
> calculations with restraints like this:
>
> &rst iat=8879, 8458, r2=2.625, rk2=50, r2a=1.0,
> /
>
> With the jar option set to 1 for SMD, the missing parameters will be set
> automatically. In the output, the restraint looks like the following:
>
> jar option running
> ******
>  H82 ( 8879)-OH  ( 8458)                            NSTEP1=     0
> NSTEP2=500000
> R1 = -97.375 R2 =   2.625 R3 =   2.625 R4 = 102.625 RK2 =  50.000 RK3 =
> 50.000
> R1A= -99.000 R2A=   1.000 R3A=   1.000 R4A= 101.000 RK2A=  50.000 RK3A=
> 50.000
>  Rcurr:    2.626  Rcurr-(R2+R3)/2:    0.001  MIN(Rcurr-R2,Rcurr-R3):    0.001
>                       Number of restraints read =     1
>
> Now i want to start a SMD with two different restraints running in parallel
> over the time of a MD (described in the manual p. 168f ?). Goal is the same
> as  doing a normal SMD, a free energy calculation. So i thought just adding
> another &rst line to the REST-file would work, but i only get an error
> message or only the first restraint is recognized.
>
> Input .REST:
>
> &rst iat=4676, 1583 r2=3.792, rk2=50, r2a=1.00,
> &rst iat=4657, 4671 r2=3.897, rk2=50, r2a=1.5,
> /
>
> Output:
>
>  jar option running
> ******
>  H5  ( 4676)-OD1 ( 1583)                            NSTEP1=     0
> NSTEP2=250000
> R1 = -96.208 R2 =   3.792 R3 =   3.792 R4 = 103.792 RK2 =  50.000 RK3 =
> 50.000
> R1A= -99.000 R2A=   1.000 R3A=   1.000 R4A= 101.000 RK2A=  50.000 RK3A=
> 50.000
>  Rcurr:    3.792  Rcurr-(R2+R3)/2:    0.000  MIN(Rcurr-R2,Rcurr-R3):    0.000
>                       Number of restraints read =     1
>
>                    Done reading weight changes/NMR restraints
>
>
>
> I hope that someone tried a similar task or has an example of such
> restraint(s) so i can get an idea of how to fit my values to the required
> format given in the manual.
>
> Thanks,
> Felix Rausch
>
>
>
> -----Original Message-----
> From:   amber-bounces.ambermd.org on behalf of Carlos Simmerling
> Sent:   Mon 3/9/2009 4:13 PM
> To:     AMBER Mailing List
> Cc:
> Subject:        Re: [AMBER] generalized distance restraint
> does the restraint you sent actually work? I would think maybe no, due
> to missing commas and not defining some of the variables like r3 etc.
> maybe the defaults are ok, but read the sander output carefully to
> make sure it is exactly what you want.
> regarding multiple restraints, it is certainly possible to set
> multiple restraints and have them all changing at the same time.
> whether you need "generalized" restraints depends on what you are
> trying to do, which you haven't really said. is this for a free energy
> calculation? do you need a single restraint that changes multiple
> distances? try to clarify and more people might be able to help out.
>
>
>
> On Mon, Mar 9, 2009 at 9:48 AM, Rausch, Felix <frausch.ipb-halle.de> wrote:
>>
>> Dear amber users,
>>
>> I already started some Steered MD caclulations. Since I cant get the
>> makeDIST_RST program work properly I generated the REST-files by hand. They
>> look like the following:
>>
>>  &rst iat=4676, 1583 r2=3.792, rk2=50, r2a=1.00,
>>  /
>>
>> Now i want to set up a calculation with 2 constraints at the same time,
>> something like "Decrease distance between atoms A and B while increasing
>> distance between atoms C and D". I read in the manual that this is possible
>> by the use of a generalized distance restraint constraint.
>>
>> Is there anybody who already set up such a job who can maybe help me
>> generating a REST-file for this task? Despite reading the manual, im not
> sure
>> how to modify my REST-file to set the right parameters.
>>
>> Thanks in advance,
>> Felix Rausch
>>
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Received on Wed Mar 11 2009 - 01:11:48 PDT
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