---
name: "tpbconv_d"
section: "1"
platform: "linux"
package: "gromacs-data"
version: "5.0.2-1"
release: "Debian 8 (Jessie)"
platforms: ["linux"]
url: "https://new.carta.tech/gmx-convert-tpr"
---

# tpbconv\_d(1)

Make a modifed run-input file

Part of [gmx-convert-tpr(1)](/gmx-convert-tpr/1.md).

## NAME

gmx-convert-tpr - Make a modifed run-input file

## SYNOPSIS

gmx convert-tpr \[-s \[\<.tpr/.tpb/...\>\]\] \[-f \[\<.trr/.cpt/...\>\]\]\
              \[-e \[\<.edr\>\]\] \[-n \[\<.ndx\>\]\] \[-o \[\<.tpr/.tpb/...\>\]\]\
              \[-nice \<int\>\] \[-extend \<real\>\] \[-until \<real\>\]\
              \[-nsteps \<int\>\] \[-time \<real\>\] \[-\[no\]zeroq\] \[-\[no\]vel\]\
              \[-\[no\]cont\] \[-init\_fep\_state \<int\>\]

## DESCRIPTION

**gmx convert-tpr** can edit run input files in four ways.

**1.** by modifying the number of steps in a run input file with options **-extend**, **-until** or **-nsteps** (nsteps=-1 means unlimited number of steps)

**2.** (OBSOLETE) by creating a run input file for a continuation run when your simulation has crashed due to e.g. a full disk, or by making a continuation run input file. This option is obsolete, since mdrun now writes and reads checkpoint files. **Note** that a frame with coordinates and velocities is needed. When pressure and/or Nose-Hoover temperature coupling is used an energy file can be supplied to get an exact continuation of the original run.

**3.** by creating a **.tpx** file for a subset of your original tpx file, which is useful when you want to remove the solvent from your **.tpx** file, or when you want to make e.g. a pure Calpha **.tpx** file. Note that you may need to use **-nsteps -1** (or similar) to get this to work. **WARNING: this .tpx** file is not fully functional.

**4.** by setting the charges of a specified group to zero. This is useful when doing free energy estimates using the LIE (Linear Interaction Energy) method.

## OPTIONS

Options to specify input and output files:

**-s** *\[\<.tpr/.tpb/...\>\] (topol.tpr) (Input)*\
     Run input file: tpr tpb tpa

**-f** *\[\<.trr/.cpt/...\>\] (traj.trr) (Input, Optional)*\
     Full precision trajectory: trr cpt trj tng

**-e** *\[\<.edr\>\] (ener.edr) (Input, Optional)*\
     Energy file

**-n** *\[\<.ndx\>\] (index.ndx) (Input, Optional)*\
     Index file

**-o** *\[\<.tpr/.tpb/...\>\] (tpxout.tpr) (Output)*\
     Run input file: tpr tpb tpa

Other options:

**-nice** *\<int\> (0)*\
     Set the nicelevel

**-extend** *\<real\> (0)*\
     Extend runtime by this amount (ps)

**-until** *\<real\> (0)*\
     Extend runtime until this ending time (ps)

**-nsteps** *\<int\> (0)*\
     Change the number of steps

**-time** *\<real\> (-1)*\
     Continue from frame at this time (ps) instead of the last frame

**-\[no\]zeroq**  *(no)*\
     Set the charges of a group (from the index) to zero

**-\[no\]vel**  *(yes)*\
     Require velocities from trajectory

**-\[no\]cont**  *(yes)*\
     For exact continuation, the constraints should not be applied before the first step

**-init\_fep\_state** *\<int\> (0)*\
     fep state to initialize from

## SEE ALSO

**[gromacs(7)](/gromacs/7.md)**

More information about **GROMACS** is available at \<*http://www.gromacs.org/*\>.