---
name: "mdconvert-mdtraj"
section: "1"
platform: "linux"
package: "python3-mdtraj"
version: "1.10.3-2+b1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/mdconvert-mdtraj"
---

# mdconvert-mdtraj(1)

use mdtraj to convert molecular dynamics trajectories between formats

## NAME

mdconvert-mdtraj - use mdtraj to convert molecular dynamics trajectories between formats

## DESCRIPTION

usage: mdconvert-mdtraj \[-h\] **-o** OUTPUT \[-c CHUNK\] \[-f\] \[-s STRIDE\] \[-i INDEX\]

-

  \[-a ATOM\_INDICES\] \[-t TOPOLOGY\] input \[input ...\]

Convert molecular dynamics trajectories between formats. The DCD, XTC, TRR, PDB, binpos, NetCDF, binpos, LH5, and HDF5 formats are supported (.dcd, .xtc, .trr, .binpos, .nc, .netcdf, .h5, .lh5, .pdb)

### positional arguments:

- input

  path to one or more trajectory files. Multiple trajectories, if supplied, will be concatenated together in the output file in the order supplied. all of the trajectories should be in the same format. the format will be detected based on the file extension

### required arguments:

- **-o** OUTPUT, **--output** OUTPUT

  path to the save the output. the output format will chosen based on the file extension (.dcd, .xtc, .trr, .binpos, .nc, .netcdf, .h5, .lh5, .pdb)

### optional arguments:

- **-h**, **--help**

  show this help message and exit

- **-c** CHUNK, **--chunk** CHUNK

  number of frames to read in at once. this determines the memory requirements of this code. default=1000

- **-f**, **--force**

  force overwrite if output already exsits

- **-s** STRIDE, **--stride** STRIDE

  load only every stride-th frame from the input file(s), to subsample.

- **-i** INDEX, **--index** INDEX

  load a \*specific\* set of frames. flexible, but inefficient for a large trajectory. specify your selection using (pythonic) "slice notation" e.g. '-i N' to load the the Nth frame, '-i **-1**' will load the last frame, '-i N:M to load frames N to M, etc. see http://bit.ly/143kloq for details on the notation

- **-a** ATOM\_INDICES, **--atom\_indices** ATOM\_INDICES

  load only specific atoms from the input file(s). provide a path to file containing a space, tab or newline separated list of the (zero-based) integer indices corresponding to the atoms you wish to keep.

- **-t** TOPOLOGY, **--topology** TOPOLOGY

  path to a PDB/prmtop file. this will be used to parse the topology of the system. it's optional, but useful. if specified, it enables you to output the coordinates of your dcd/xtc/trr/netcdf/binpos as a PDB file. If you're converting \*to\* .h5, the topology will be stored inside the h5 file.