</PRE>

<UL><LI>ID = user-assigned name for the region 

<LI>style = <I>block</I> or <I>cylinder</I> or <I>prism</I> or <I>sphere</I> or <I>union</I> or <I>intersect</I> 

<LI>style = <I>block</I> or <I>cone</I> or <I>cylinder</I> or <I>prism</I> or <I>sphere</I> or <I>union</I> or <I>intersect</I> 

<PRE>  <I>block</I> args = xlo xhi ylo yhi zlo zhi

      xlo,xhi,ylo,yhi,zlo,zhi = bounds of block in all

        dimensions (distance units)

<PRE>  <I>block</I> args = dim c1 c2 radlo radhi lo hi

    xlo,xhi,ylo,yhi,zlo,zhi = bounds of block in all dimensions (distance units)

  <I>cone</I> args = xlo xhi ylo yhi zlo zhi

    dim = <I>x</I> or <I>y</I> or <I>z</I> = axis of cone

    c1,c2 = coords of cone axis in other 2 dimensions (distance units)

    radlo,radhi = cone radii at lo and hi end (distance units)

    lo,hi = bounds of cone in dim (distance units)

  <I>cylinder</I> args = dim c1 c2 radius lo hi

    dim = <I>x</I> or <I>y</I> or <I>z</I> = axis of cylinder

    c1,c2 = coords of cylinder axis in other 2 dimensions (distance units)

in the region can be identified as a group via the <A HREF = "group.html">group</A>

command, or deleted via the <A HREF = "delete_atoms.html">delete_atoms</A> command.

</P>

<P>The lo/hi values for <I>block</I> or <I>cylinder</I> or <I>prism</I> styles can be

specified as EDGE or INF.  EDGE means they extend all the way to the

global simulation box boundary.  Note that this is the current box

boundary; if the box changes size during a simulation the region does

not.  INF means a large negative or positive number (1.0e20), so it

should encompass the simulation box even if it changes size.  If a

<P>The lo/hi values for <I>block</I> or <I>cone</I> or <I>cylinder</I> or <I>prism</I> styles

can be specified as EDGE or INF.  EDGE means they extend all the way

to the global simulation box boundary.  Note that this is the current

box boundary; if the box changes size during a simulation, the region

does not.  INF means a large negative or positive number (1.0e20), so

it should encompass the simulation box even if it changes size.  If a

region is defined before the simulation box has been created (via

<A HREF = "create_box.html">create_box</A> or <A HREF = "read_data.html">read_data</A> or

<A HREF = "read_restart.html">read_restart</A> commands), then an EDGE or INF

parameter cannot be used.

</P>

<P>For style <I>cylinder</I>, the c1,c2 params are coordinates in the 2 other

dimensions besides the cylinder axis dimension.  For dim = x, c1/c2 =

y/z; for dim = y, c1/c2 = x/z; for dim = z, c1/c2 = x/y.  Thus the

third example above specifies a cylinder with its axis in the

<P>For style <I>cone</I>, an axis-aligned cone is defined which is like a

<I>cylinder</I> except that two different radii (one at each end) can be

defined.

</P>

<P>For style <I>cone</I> and <I>cylinder</I>, the c1,c2 params are coordinates in

the 2 other dimensions besides the cylinder axis dimension.  For dim =

x, c1/c2 = y/z; for dim = y, c1/c2 = x/z; for dim = z, c1/c2 = x/y.

Thus the third example above specifies a cylinder with its axis in the

y-direction located at x = 2.0 and z = 3.0, with a radius of 5.0, and

extending in the y-direction from -5.0 to the upper box boundary.

</P>

region ID style args keyword value ... :pre

ID = user-assigned name for the region :ulb,l

style = {block} or {cylinder} or {prism} or {sphere} or {union} or {intersect} :l

  {block} args = xlo xhi ylo yhi zlo zhi

      xlo,xhi,ylo,yhi,zlo,zhi = bounds of block in all

        dimensions (distance units)

style = {block} or {cone} or {cylinder} or {prism} or {sphere} or {union} or {intersect} :l

  {block} args = dim c1 c2 radlo radhi lo hi

    xlo,xhi,ylo,yhi,zlo,zhi = bounds of block in all dimensions (distance units)

  {cone} args = xlo xhi ylo yhi zlo zhi

    dim = {x} or {y} or {z} = axis of cone

    c1,c2 = coords of cone axis in other 2 dimensions (distance units)

    radlo,radhi = cone radii at lo and hi end (distance units)

    lo,hi = bounds of cone in dim (distance units)

  {cylinder} args = dim c1 c2 radius lo hi

    dim = {x} or {y} or {z} = axis of cylinder

    c1,c2 = coords of cylinder axis in other 2 dimensions (distance units)

in the region can be identified as a group via the "group"_group.html

command, or deleted via the "delete_atoms"_delete_atoms.html command.

The lo/hi values for {block} or {cylinder} or {prism} styles can be

specified as EDGE or INF.  EDGE means they extend all the way to the

global simulation box boundary.  Note that this is the current box

boundary; if the box changes size during a simulation the region does

not.  INF means a large negative or positive number (1.0e20), so it

should encompass the simulation box even if it changes size.  If a

The lo/hi values for {block} or {cone} or {cylinder} or {prism} styles

can be specified as EDGE or INF.  EDGE means they extend all the way

to the global simulation box boundary.  Note that this is the current

box boundary; if the box changes size during a simulation, the region

does not.  INF means a large negative or positive number (1.0e20), so

it should encompass the simulation box even if it changes size.  If a

region is defined before the simulation box has been created (via

"create_box"_create_box.html or "read_data"_read_data.html or

"read_restart"_read_restart.html commands), then an EDGE or INF

parameter cannot be used.

For style {cylinder}, the c1,c2 params are coordinates in the 2 other

dimensions besides the cylinder axis dimension.  For dim = x, c1/c2 =

y/z; for dim = y, c1/c2 = x/z; for dim = z, c1/c2 = x/y.  Thus the

third example above specifies a cylinder with its axis in the

For style {cone}, an axis-aligned cone is defined which is like a

{cylinder} except that two different radii (one at each end) can be

defined.

For style {cone} and {cylinder}, the c1,c2 params are coordinates in

the 2 other dimensions besides the cylinder axis dimension.  For dim =

x, c1/c2 = y/z; for dim = y, c1/c2 = x/z; for dim = z, c1/c2 = x/y.

Thus the third example above specifies a cylinder with its axis in the

y-direction located at x = 2.0 and z = 3.0, with a radius of 5.0, and

extending in the y-direction from -5.0 to the upper box boundary.