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<CENTER><A HREF = "http://lammps.sandia.gov">LAMMPS WWW Site</A> - <A HREF = "Manual.html">LAMMPS Documentation</A> - <A HREF = "Section_commands.html#comm">LAMMPS Commands</A>
</CENTER>
<HR>
<H3>timestep command
</H3>
<P><B>Syntax:</B>
</P>
<PRE>timestep dt
</PRE>
<UL><LI>dt = timestep size (time units)
</UL>
<P><B>Examples:</B>
</P>
<PRE>timestep 2.0
timestep 0.003
</PRE>
<P><B>Description:</B>
</P>
<P>Set the timestep size for subsequent molecular dynamics simulations.
See the <A HREF = "units.html">units</A> command for the time units associated with
each choice of units that LAMMPS supports.
</P>
<P>The default value for the timestep size also depends on the choice of
units for the simulation; see the default values below.
</P>
<P>When the <A HREF = "run_style.html">run style</A> is <I>respa</I>, dt is the timestep for
the outer loop (largest) timestep.
</P>
<P><B>Restrictions:</B> none
</P>
<P><B>Related commands:</B>
</P>
<P><A HREF = "fix_dt_reset.html">fix dt/reset</A>, <A HREF = "run.html">run</A>,
<A HREF = "run_style.html">run_style</A> respa, <A HREF = "units.html">units</A>
</P>
<P><B>Default:</B>
</P>
<DIV ALIGN=left ><TABLE BORDER=1 >
<TR ALIGN="center"><TD >choice of <A HREF = "units.html">units</A> </TD><TD > time units </TD><TD > default timestep size</TD></TR>
<TR ALIGN="center"><TD >lj </TD><TD > tau </TD><TD > 0.005 tau</TD></TR>
<TR ALIGN="center"><TD >real </TD><TD > fmsec </TD><TD > 1.0 fmsec</TD></TR>
<TR ALIGN="center"><TD >metal </TD><TD > psec </TD><TD > 0.001 psec</TD></TR>
<TR ALIGN="center"><TD >si </TD><TD > sec </TD><TD > 1.0e-8 sec (10 nsec)</TD></TR>
<TR ALIGN="center"><TD >cgs </TD><TD > sec </TD><TD > 1.0e-8 sec (10 nsec)</TD></TR>
<TR ALIGN="center"><TD >electron </TD><TD > fmsec </TD><TD > 0.001 fmsec</TD></TR>
<TR ALIGN="center"><TD >micro </TD><TD > usec </TD><TD > 2.0 usec</TD></TR>
<TR ALIGN="center"><TD >nano </TD><TD > nsec </TD><TD > 0.00045 nsec
</TD></TR></TABLE></DIV>
</HTML>
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