Page Menu
Home
c4science
Search
Configure Global Search
Log In
Files
F71051040
angle_charmm.html
No One
Temporary
Actions
Download File
Edit File
Delete File
View Transforms
Subscribe
Mute Notifications
Award Token
Subscribers
None
File Metadata
Details
File Info
Storage
Attached
Created
Tue, Jul 9, 08:35
Size
3 KB
Mime Type
text/html
Expires
Thu, Jul 11, 08:35 (1 d, 22 h)
Engine
blob
Format
Raw Data
Handle
18900206
Attached To
rLAMMPS lammps
angle_charmm.html
View Options
<HTML>
<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>angle_style charmm command
</H3>
<H3>angle_style charmm/omp command
</H3>
<P><B>Syntax:</B>
</P>
<PRE>angle_style charmm
</PRE>
<P><B>Examples:</B>
</P>
<PRE>angle_style charmm
angle_coeff 1 300.0 107.0 50.0 3.0
</PRE>
<P><B>Description:</B>
</P>
<P>The <I>charmm</I> angle style uses the potential
</P>
<CENTER><IMG SRC = "Eqs/angle_charmm.jpg">
</CENTER>
<P>with an additional Urey_Bradley term based on the distance <I>r</I> between
the 1st and 3rd atoms in the angle. K, theta0, Kub, and Rub are
coefficients defined for each angle type.
</P>
<P>See <A HREF = "#MacKerell">(MacKerell)</A> for a description of the CHARMM force
field.
</P>
<P>The following coefficients must be defined for each angle type via the
<A HREF = "angle_coeff.html">angle_coeff</A> command as in the example above, or in
the data file or restart files read by the <A HREF = "read_data.html">read_data</A>
or <A HREF = "read_restart.html">read_restart</A> commands:
</P>
<UL><LI>K (energy/radian^2)
<LI>theta0 (degrees)
<LI>K_ub (energy/distance^2)
<LI>r_ub (distance)
</UL>
<P>Theta0 is specified in degrees, but LAMMPS converts it to radians
internally; hence the units of K are in energy/radian^2.
</P>
<HR>
<P>Styles with a <I>cuda</I>, <I>gpu</I>, <I>omp</I>, or <I>opt</I> suffix are functionally
the same as the corresponding style without the suffix. They have
been optimized to run faster, depending on your available hardware,
as discussed in <A HREF = "Section_accelerate.html">this section</A> of the manual.
The accelerated styles take the same arguments and should produce the
same results, except for round-off and precision issues.
</P>
<P>These accelerated styles are part of the USER-CUDA, GPU, USER-OMP and OPT
packages, respectively. They are only enabled if LAMMPS was built with
those packages. See the <A HREF = "Section_start.html#start_3">Making LAMMPS</A>
section for more info.
</P>
<P>You can specify the accelerated styles explicitly in your input script
by including their suffix, or you can use the <A HREF = "Section_start.html#start_6">-suffix command-line
switch</A> when you invoke LAMMPS, or you can
use the <A HREF = "suffix.html">suffix</A> command in your input script.
</P>
<P>See <A HREF = "Section_accelerate.html">this section</A> of the manual for more
instructions on how to use the accelerated styles effectively.
</P>
<HR>
<P><B>Restrictions:</B>
</P>
<P>This angle style can only be used if LAMMPS was built with the
MOLECULAR package (which it is by default). See the <A HREF = "Section_start.html#start_3">Making
LAMMPS</A> section for more info on packages.
</P>
<P><B>Related commands:</B>
</P>
<P><A HREF = "angle_coeff.html">angle_coeff</A>
</P>
<P><B>Default:</B> none
</P>
<HR>
<A NAME = "MacKerell"></A>
<P><B>(MacKerell)</B> MacKerell, Bashford, Bellott, Dunbrack, Evanseck, Field,
Fischer, Gao, Guo, Ha, et al, J Phys Chem, 102, 3586 (1998).
</P>
</HTML>
Event Timeline
Log In to Comment