| ## gmxcheck Main Table of Contents | VERSION 3.2.0 Sun 25 Jan 2004

### Description

gmxcheck reads a trajectory (`.trj`, `.trr` or `.xtc`) or an energy file (`.ene` or `.edr`) and prints out useful information about them.

Option `-c` checks for presence of coordinates, velocities and box in the file, for close contacts (smaller than `-vdwfac` and not bonded, i.e. not between `-bonlo` and `-bonhi`, all relative to the sum of both Van der Waals radii) and atoms outside the box (these may occur often and are no problem). If velocities are present, an estimated temperature will be calculated from them.

The program will compare run input (`.tpr`, `.tpb` or `.tpa`) files when both `-s1` and `-s2` are supplied. Similarly a pair of trajectory files can be compared (using the `-f2` option), or a pair of energy files (using the `-e2` option).

### Files

option | filename | type | description
--- | --- | --- | ---
`-f` | `traj.xtc` | Input, Opt. | Generic trajectory: xtc trr trj gro g96 pdb
`-f2` | `traj.xtc` | Input, Opt. | Generic trajectory: xtc trr trj gro g96 pdb
`-s1` | `top1.tpr` | Input, Opt. | Generic run input: tpr tpb tpa xml
`-s2` | `top2.tpr` | Input, Opt. | Generic run input: tpr tpb tpa xml
`-c` | `topol.tpr` | Input, Opt. | Structure+mass(db): tpr tpb tpa gro g96 pdb xml
`-e` | `ener.edr` | Input, Opt. | Generic energy: edr ene
`-e2` | `ener2.edr` | Input, Opt. | Generic energy: edr ene

### Other options

option | type | default | description
--- | --- | --- | ---
`-[no]h` | bool | `no` | Print help info and quit
`-nice` | int | `0` | Set the nicelevel
`-vdwfac` | real | `0.8` | Fraction of sum of VdW radii used as warning cutoff
`-bonlo` | real | `0.4` | Min. fract. of sum of VdW radii for bonded atoms
`-bonhi` | real | `0.7` | Max. fract. of sum of VdW radii for bonded atoms
`-tol` | real | `0` | Relative tolerance for comparing real values defined as 2*(a-b)/(|a|+|b|)
`-lastener` | string | `` | Last energy term to compare (if not given all are tested). It makes sense to go up until the Pressure.

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