git-svn-id: svn://svn.icms.temple.edu/lammps-ro/trunk@1908 f3b2605a-c512-4ea7-a41b-209d697bcdaa
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@ -55,9 +55,23 @@ performed, but appears to be more robust than previous line searches
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we've tried. The backtracking method is described in Nocedal and
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we've tried. The backtracking method is described in Nocedal and
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Wright's Numerical Optimization (Procedure 3.1 on p 41).
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Wright's Numerical Optimization (Procedure 3.1 on p 41).
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</P>
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</P>
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<P>Note that these algorithms only find a local energy minimum from a
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<P>The objective function being minimized is the potential energy of the
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given starting point (configuration of atoms). There is no guarantee
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system as a function of atom coordinates:
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of finding a global energy minimum.
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</P>
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<CENTER><IMG SRC = "Eqs/min_energy.jpg">
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</CENTER>
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<P>where the first term is the sum of all non-bonded pairwise
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interactions including long-range interactions (Coulombic), the 2nd
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thru fifth terms are bond, angle, dihedral, and improper interactions
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respectively, and the last term is constraints due to fixes, such as
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energy/force interactions with a wall. See the discussion below about
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which fix commands affect minimization.
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</P>
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<P>The starting point for the minimization is the current configuration
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of the atoms. Note that the minimizer only attempts to find a local
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energy minimum, not a global minimum. In a mathematical sense, there
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is no guarantee of even finding a local minimum in some cases with
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these algorithms.
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</P>
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</P>
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<HR>
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<HR>
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@ -132,7 +146,7 @@ reduced.
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</P>
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</P>
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<HR>
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<HR>
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<P>IMPORTANT NOTE: It is HIGHLY RECOMMENDED that you use a <A HREF = "pair_style.html">pair
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<P>IMPORTANT NOTE: It is highly recommended that you use a <A HREF = "pair_style.html">pair
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style</A> that goes to 0.0 at the cutoff distance when
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style</A> that goes to 0.0 at the cutoff distance when
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performing minimization (even if you later change it when running
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performing minimization (even if you later change it when running
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dynamics). If this is not done, the total energy of the system will
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dynamics). If this is not done, the total energy of the system will
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@ -52,9 +52,23 @@ performed, but appears to be more robust than previous line searches
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we've tried. The backtracking method is described in Nocedal and
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we've tried. The backtracking method is described in Nocedal and
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Wright's Numerical Optimization (Procedure 3.1 on p 41).
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Wright's Numerical Optimization (Procedure 3.1 on p 41).
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Note that these algorithms only find a local energy minimum from a
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The objective function being minimized is the potential energy of the
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given starting point (configuration of atoms). There is no guarantee
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system as a function of atom coordinates:
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of finding a global energy minimum.
|
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:c,image(Eqs/min_energy.jpg)
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where the first term is the sum of all non-bonded pairwise
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interactions including long-range interactions (Coulombic), the 2nd
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thru fifth terms are bond, angle, dihedral, and improper interactions
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respectively, and the last term is constraints due to fixes, such as
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energy/force interactions with a wall. See the discussion below about
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which fix commands affect minimization.
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The starting point for the minimization is the current configuration
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of the atoms. Note that the minimizer only attempts to find a local
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energy minimum, not a global minimum. In a mathematical sense, there
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is no guarantee of even finding a local minimum in some cases with
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these algorithms.
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|
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:line
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:line
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@ -129,7 +143,7 @@ The iterations and force evaluation values are what is checked by the
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:line
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:line
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IMPORTANT NOTE: It is HIGHLY RECOMMENDED that you use a "pair
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IMPORTANT NOTE: It is highly recommended that you use a "pair
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style"_pair_style.html that goes to 0.0 at the cutoff distance when
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style"_pair_style.html that goes to 0.0 at the cutoff distance when
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performing minimization (even if you later change it when running
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performing minimization (even if you later change it when running
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dynamics). If this is not done, the total energy of the system will
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dynamics). If this is not done, the total energy of the system will
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