## GROMACS 4.6
Online Reference

VERSION 4.6
Sat 19 Jan 2013

### General

Getting Started
Flow Chart
File Formats
mdp options
FAQ

### Programs

Options
do_dssp
editconf
eneconv
g_anadock
g_anaeig
g_analyze
g_angle
g_bar
g_bond
g_bundle
g_chi
g_cluster
g_clustsize
g_confrms
g_covar
g_current
g_density
g_densmap
g_densorder
g_dielectric
g_dih
g_dipoles
g_disre
g_dist
g_dos
g_dyecoupl
g_dyndom
genbox
genconf
g_enemat
g_energy
genion
genrestr
g_filter
g_gyrate
g_h2order
g_hbond
g_helix
g_helixorient
g_hydorder
g_kinetics
g_lie
g_luck
g_mdmat
g_membed
g_mindist
g_morph
g_msd
gmxcheck
gmxdump
g_nmeig
g_nmens
g_nmtraj
g_options
g_order
g_pme_error
g_polystat
g_potential
g_principal
g_protonate
g_rama
g_rdf
g_rms
g_rmsdist
g_rmsf
grompp
g_rotacf
g_rotmat
g_saltbr
g_sans
g_sas
g_select
g_sgangle
g_sham
g_sigeps
g_sorient
g_spatial
g_spol
g_tcaf
g_traj
g_tune_pme
g_vanhove
g_velacc
g_wham
g_wheel
g_x2top
make_edi
make_ndx
mdrun
mk_angndx
pdb2gmx
tpbconv
trjcat
trjconv
trjorder
xpm2ps

### Programs by Topic

Generating topologies and coordinates
Running a simulation
Viewing trajectories
Processing energies
Converting files
Tools
Distances between structures
Distances in structures over time
Mass distribution properties over time
Analyzing bonded interactions
Structural properties
Kinetic properties
Electrostatic properties
Protein-specific analysis
Interfaces
Covariance analysis
Normal modes

Generating topologies and coordinates
editconf | edits the box and writes subgroups
g_protonate | protonates structures
g_x2top | generates a primitive topology from coordinates
genbox | solvates a system
genconf | multiplies a conformation in 'random' orientations
genion | generates mono atomic ions on energetically favorable positions
genrestr | generates position restraints or distance restraints for index groups
pdb2gmx | converts coordinate files to topology and FF-compliant coordinate files

Running a simulation
grompp | makes a run input file
mdrun | performs a simulation, do a normal mode analysis or an energy minimization
tpbconv | makes a run input file for restarting a crashed run

Viewing trajectories
g_nmtraj | generate a virtual trajectory from an eigenvector
ngmx | displays a trajectory

Processing energies
g_enemat | extracts an energy matrix from an energy file
g_energy | writes energies to xvg files and displays averages
mdrun | with -rerun (re)calculates energies for trajectory frames

Converting files
editconf | converts and manipulates structure files
eneconv | converts energy files
g_sigeps | convert c6/12 or c6/cn combinations to and from sigma/epsilon
trjcat | concatenates trajectory files
trjconv | converts and manipulates trajectory files
xpm2ps | converts XPM matrices to encapsulated postscript (or XPM)

Tools
g_analyze | analyzes data sets
g_dyndom | interpolate and extrapolate structure rotations
g_filter | frequency filters trajectories, useful for making smooth movies
g_lie | free energy estimate from linear combinations
g_morph | linear interpolation of conformations
g_pme_error | estimates the error of using PME with a given input file
g_select | selects groups of atoms based on flexible textual selections
g_sham | read/write xmgr and xvgr data sets
g_spatial | calculates the spatial distribution function
g_traj | plots x, v and f of selected atoms/groups (and more) from a trajectory
g_tune_pme | time mdrun as a function of PME nodes to optimize settings
g_wham | weighted histogram analysis after umbrella sampling
gmxcheck | checks and compares files
gmxdump | makes binary files human readable
make_ndx | makes index files
mk_angndx | generates index files for g_angle
trjorder | orders molecules according to their distance to a group
xpm2ps | convert XPM (XPixelMap) file to postscript

Distances between structures
g_cluster | clusters structures
g_confrms | fits two structures and calculates the rmsd
g_rms | calculates rmsd's with a reference structure and rmsd matrices
g_rmsf | calculates atomic fluctuations

Distances in structures over time
g_bond | calculates distances between atoms
g_dist | calculates the distances between the centers of mass of two groups
g_mindist | calculates the minimum distance between two groups
g_mdmat | calculates residue contact maps
g_polystat | calculates static properties of polymers
g_rmsdist | calculates atom pair distances averaged with power -2, -3 or -6

Mass distribution properties over time
g_gyrate | calculates the radius of gyration
g_msd | calculates mean square displacements
g_polystat | calculates static properties of polymers
g_rdf | calculates radial distribution functions
g_rotacf | calculates the rotational correlation function for molecules
g_rotmat | plots the rotation matrix for fitting to a reference structure
g_sans | computes the small angle neutron scattering spectra
g_traj | plots x, v, f, box, temperature and rotational energy
g_vanhove | calculates Van Hove displacement functions

Analyzing bonded interactions
g_angle | calculates distributions and correlations for angles and dihedrals
g_bond | calculates bond length distributions
mk_angndx | generates index files for g_angle

Structural properties
g_anadock | cluster structures from Autodock runs
g_bundle | analyzes bundles of axes, e.g. helices
g_clustsize | calculate size distributions of atomic clusters
g_disre | analyzes distance restraints
g_hbond | computes and analyzes hydrogen bonds
g_order | computes the order parameter per atom for carbon tails
g_principal | calculates axes of inertia for a group of atoms
g_rdf | calculates radial distribution functions
g_saltbr | computes salt bridges
g_sas | computes solvent accessible surface area
g_sgangle | computes the angle and distance between two groups
g_sorient | analyzes solvent orientation around solutes
g_spol | analyzes solvent dipole orientation and polarization around solutes

Kinetic properties
g_bar | calculates free energy difference estimates through Bennett's acceptance ratio
g_current | calculate current autocorrelation function of system
g_dos | analyzes density of states and properties based on that
g_dyecoupl | extracts dye dynamics from trajectories
g_kinetics | analyzes kinetic constants from properties based on the Eyring model
g_principal | calculate principal axes of inertion for a group of atoms
g_tcaf | calculates viscosities of liquids
g_traj | plots x, v, f, box, temperature and rotational energy
g_vanhove | compute Van Hove correlation function
g_velacc | calculates velocity autocorrelation functions

Electrostatic properties
g_current | calculates dielectric constants for charged systems
g_dielectric | calculates frequency dependent dielectric constants
g_dipoles | computes the total dipole plus fluctuations
g_potential | calculates the electrostatic potential across the box
g_spol | analyze dipoles around a solute
genion | generates mono atomic ions on energetically favorable positions

Protein-specific analysis
do_dssp | assigns secondary structure and calculates solvent accessible surface area
g_chi | calculates everything you want to know about chi and other dihedrals
g_helix | calculates basic properties of alpha helices
g_helixorient | calculates local pitch/bending/rotation/orientation inside helices
g_rama | computes Ramachandran plots
g_wheel | plots helical wheels
g_xrama | shows animated Ramachandran plots

Interfaces
g_bundle | analyzes bundles of axes, e.g. transmembrane helices
g_density | calculates the density of the system
g_densmap | calculates 2D planar or axial-radial density maps
g_densorder | calculate surface fluctuations
g_h2order | computes the orientation of water molecules
g_hydorder | computes tetrahedrality parameters around a given atom
g_order | computes the order parameter per atom for carbon tails
g_membed | embeds a protein into a lipid bilayer
g_potential | calculates the electrostatic potential across the box

Covariance analysis
g_anaeig | analyzes the eigenvectors
g_covar | calculates and diagonalizes the covariance matrix
make_edi | generate input files for essential dynamics sampling

Normal modes
g_anaeig | analyzes the normal modes
g_nmeig | diagonalizes the Hessian
g_nmtraj | generate oscillating trajectory of an eigenmode
g_nmens | generates an ensemble of structures from the normal modes
grompp | makes a run input file
mdrun | finds a potential energy minimum and calculates the Hessian

http://www.gromacs.org