# timestep command¶

## Syntax¶

timestep dt

• dt = timestep size (time units)

## Examples¶

timestep 2.0
timestep 0.003


## Description¶

Set the timestep size for subsequent molecular dynamics simulations. See the units command for the time units associated with each choice of units that LAMMPS supports.

The default value for the timestep size also depends on the choice of units for the simulation; see the default values below.

When the run style is respa, dt is the timestep for the outer loop (largest) timestep.

none

## Default¶

 choice of units time units default timestep size lj $$\tau$$ 0.005 $$\tau$$ real fs 1.0 fs metal ps 0.001 ps si s 1.0e-8 s (10 ns) cgs s 1.0e-8 s (10 ns) electron fs 0.001 fs micro $$\mu$$s 2.0 $$\mu$$s nano ns 0.00045 ns