---
name: "gmx-eneconv"
section: "1"
platform: "linux"
package: "gromacs-data"
version: "2025.2-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/gmx-eneconv"
---

# gmx-eneconv(1)

Convert energy files

## NAME

gmx-eneconv - Convert energy files

## SYNOPSIS

```
gmx eneconv [-f [<.edr> [...]]] [-o [<.edr>]] [-b <real>] [-e <real>]
            [-dt <real>] [-offset <real>] [-[no]settime] [-[no]sort]
            [-[no]rmdh] [-scalefac <real>] [-[no]error]
```

## DESCRIPTION

With *multiple files* specified for the **-f** option:

Concatenates several energy files in sorted order. In the case of double time frames, the one in the later file is used. By specifying **-settime** you will be asked for the start time of each file. The input files are taken from the command line, such that the command **gmx eneconv -f \*.edr -o fixed.edr** should do the trick.

With *one file* specified for **-f**:

Reads one energy file and writes another, applying the **-dt**, **-offset**, **-t0** and **-settime** options and converting to a different format if necessary (indicated by file extensions).

**-settime** is applied first, then **-dt**/**-offset** followed by **-b** and **-e** to select which frames to write.

## OPTIONS

Options to specify input files:

- **-f \[\<.edr\> \[...\]\] (ener.edr)**

  Energy file

Options to specify output files:

- **-o \[\<.edr\>\] (fixed.edr)**

  Energy file

Other options:

- **-b \<real\> (-1)**

  First time to use

- **-e \<real\> (-1)**

  Last time to use

- **-dt \<real\> (0)**

  Only write out frame when t MOD dt = offset

- **-offset \<real\> (0)**

  Time offset for **-dt** option

- **-\[no\]settime (no)**

  Change starting time interactively

- **-\[no\]sort (yes)**

  Sort energy files (not frames)

- **-\[no\]rmdh (no)**

  Remove free energy block data

- **-scalefac \<real\> (1)**

  Multiply energy component by this factor

- **-\[no\]error (yes)**

  Stop on errors in the file

## KNOWN ISSUES

- •

  When combining trajectories the sigma and E^2 (necessary for statistics) are not updated correctly. Only the actual energy is correct. One thus has to compute statistics in another way.

## SEE ALSO

**[gmx(1)](/gmx/1.md)**

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

## COPYRIGHT

2025, GROMACS development team