+Syntax: +
+angle_style cosine/shift ++
Examples: +
+angle_style cosine/shift +angle_coeff * 10.0 45.0 ++
Description: +
+The cosine/shift angle style uses the potential +
+
+where theta0 is the equilibrium angle. The potential is bounded +between -Umin and zero. In the neighborhood of the minimum E=- Umin + +Umin/4(theta-theta0)^2 hence the spring constant is umin/2. +
+The following coefficients must be defined for each angle type via the +angle_coeff command as in the example above, or in +the data file or restart files read by the read_data +or read_restart commands: +
+Restrictions: +
+This angle style can only be used if LAMMPS was built with the +"user-misc" package. See the Making LAMMPS +section for more info on packages. +
+Related commands: +
+angle_coeff, +angle_cosineshiftexp +
+Default: none +
+ diff --git a/doc/angle_cosine_shift.txt b/doc/angle_cosine_shift.txt new file mode 100644 index 0000000000..e3e9c0c9d2 --- /dev/null +++ b/doc/angle_cosine_shift.txt @@ -0,0 +1,49 @@ +"LAMMPS WWW Site"_lws - "LAMMPS Documentation"_ld - "LAMMPS Commands"_lc :c + +:link(lws,http://lammps.sandia.gov) +:link(ld,Manual.html) +:link(lc,Section_commands.html#comm) + +:line + +angle_style cosine/shift command :h3 + +[Syntax:] + +angle_style cosine/shift :pre + +[Examples:] + +angle_style cosine/shift +angle_coeff * 10.0 45.0 :pre + +[Description:] + +The {cosine/shift} angle style uses the potential + +:c,image(Eqs/angle_cosine_shift.jpg) + +where theta0 is the equilibrium angle. The potential is bounded +between -Umin and zero. In the neighborhood of the minimum E=- Umin + +Umin/4(theta-theta0)^2 hence the spring constant is umin/2. + +The following coefficients must be defined for each angle type via the +"angle_coeff"_angle_coeff.html command as in the example above, or in +the data file or restart files read by the "read_data"_read_data.html +or "read_restart"_read_restart.html commands: + +umin (energy) +theta (angle) :ul + +[Restrictions:] + +This angle style can only be used if LAMMPS was built with the +"user-misc" package. See the "Making LAMMPS"_Section_start.html#2_3 +section for more info on packages. + +[Related commands:] + +"angle_coeff"_angle_coeff.html, +"angle_cosineshiftexp"_angle_cosineshiftexp.html + +[Default:] none diff --git a/doc/angle_cosine_shift_exp.html b/doc/angle_cosine_shift_exp.html new file mode 100644 index 0000000000..4080c115fc --- /dev/null +++ b/doc/angle_cosine_shift_exp.html @@ -0,0 +1,67 @@ + +Syntax: +
+angle_style cosine/shift/exp ++
Examples: +
+angle_style cosine/shift/exp +angle_coeff * 10.0 45.0 2.0 ++
Description: +
+The cosine/shift/exp angle style uses the potential +
+
+where Umin, theta, and a are defined for each angle type. +
+The potential is bounded between [-Umin:0] and the minimum is +located at the angle theta0. The a parameter can be both positive or +negative and is used to control the spring constant at the +equilibrium. +
+The spring constant is given by k = A exp(A) Umin / [2 (Exp(a)-1)]. +For a > 3, k/Umin = a/2 to better than 5% relative error. For negative +values of the a parameter, the spring constant is essentially zero, +and anharmonic terms takes over. The potential is furthermore well +behaved in the limit a -> 0, where it has been implemented to linear +order in a for a < 0.001. In this limit the potential reduces to the +cosineshifted potential. +
+The following coefficients must be defined for each angle type via the +angle_coeff command as in the example above, or in +the data file or restart files read by the read_data +or read_restart commands: +
+Restrictions: +
+This angle style can only be used if LAMMPS was built with the +"user-misc" package. See the Making LAMMPS +section for more info on packages. +
+Related commands: +
+angle_coeff, +angle_cosineshift, +dihedral_cosineshift +
+Default: none +
+ diff --git a/doc/angle_cosine_shift_exp.txt b/doc/angle_cosine_shift_exp.txt new file mode 100644 index 0000000000..9c190e38a1 --- /dev/null +++ b/doc/angle_cosine_shift_exp.txt @@ -0,0 +1,62 @@ +"LAMMPS WWW Site"_lws - "LAMMPS Documentation"_ld - "LAMMPS Commands"_lc :c + +:link(lws,http://lammps.sandia.gov) +:link(ld,Manual.html) +:link(lc,Section_commands.html#comm) + +:line + +angle_style cosine/shift/exp command :h3 + +[Syntax:] + +angle_style cosine/shift/exp :pre + +[Examples:] + +angle_style cosine/shift/exp +angle_coeff * 10.0 45.0 2.0 :pre + +[Description:] + +The {cosine/shift/exp} angle style uses the potential + +:c,image(Eqs/angle_cosine/shift/exp.jpg) + +where Umin, theta, and a are defined for each angle type. + +The potential is bounded between \[-Umin:0\] and the minimum is +located at the angle theta0. The a parameter can be both positive or +negative and is used to control the spring constant at the +equilibrium. + +The spring constant is given by k = A exp(A) Umin / \[2 (Exp(a)-1)\]. +For a > 3, k/Umin = a/2 to better than 5% relative error. For negative +values of the a parameter, the spring constant is essentially zero, +and anharmonic terms takes over. The potential is furthermore well +behaved in the limit a -> 0, where it has been implemented to linear +order in a for a < 0.001. In this limit the potential reduces to the +cosineshifted potential. + +The following coefficients must be defined for each angle type via the +"angle_coeff"_angle_coeff.html command as in the example above, or in +the data file or restart files read by the "read_data"_read_data.html +or "read_restart"_read_restart.html commands: + +umin (energy) +theta (angle) +A (real number) :ul + +[Restrictions:] + +This angle style can only be used if LAMMPS was built with the +"user-misc" package. See the "Making LAMMPS"_Section_start.html#2_3 +section for more info on packages. + +[Related commands:] + +"angle_coeff"_angle_coeff.html, +"angle_cosineshift"_angle_cosineshift.html, +"dihedral_cosineshift"_dihedral_cosineshift.html + +[Default:] none diff --git a/doc/bond_harmonic_shift.html b/doc/bond_harmonic_shift.html new file mode 100644 index 0000000000..f49b1042b5 --- /dev/null +++ b/doc/bond_harmonic_shift.html @@ -0,0 +1,58 @@ + +Syntax: +
+bond_style harmonic/shift ++
Examples: +
+bond_style harmonic/shift +bond_coeff 5 10.0 0.5 1.0 ++
Description: +
+The harmonic/shift bond style is a shifted harmonic bond that uses +the potential +
+
+where r0 is the equilibrium bond distance, and rc the critical distance. +The potential is -Umin at r0 and zero at rc. The spring constant is +k = Umin / [ 2 (r0-rc)^2]. +
+The following coefficients must be defined for each bond type via the +bond_coeff command as in the example above, or in +the data file or restart files read by the read_data +or read_restart commands: +
+Restrictions: +
+This bond style can only be used if LAMMPS was built with the +"user-misc" package. See the Making LAMMPS +section for more info on packages. +
+Related commands: +
+bond_coeff, delete_bonds, +bond_harmonic +
+Default: none +
+ diff --git a/doc/bond_harmonic_shift.txt b/doc/bond_harmonic_shift.txt new file mode 100644 index 0000000000..c26195b6c1 --- /dev/null +++ b/doc/bond_harmonic_shift.txt @@ -0,0 +1,51 @@ +"LAMMPS WWW Site"_lws - "LAMMPS Documentation"_ld - "LAMMPS Commands"_lc :c + +:link(lws,http://lammps.sandia.gov) +:link(ld,Manual.html) +:link(lc,Section_commands.html#comm) + +:line + +bond_style harmonic/shift command :h3 + +[Syntax:] + +bond_style harmonic/shift :pre + +[Examples:] + +bond_style harmonic/shift +bond_coeff 5 10.0 0.5 1.0 :pre + +[Description:] + +The {harmonic/shift} bond style is a shifted harmonic bond that uses +the potential + +:c,image(Eqs/bond_harmonic_shift.jpg) + +where r0 is the equilibrium bond distance, and rc the critical distance. +The potential is -Umin at r0 and zero at rc. The spring constant is +k = Umin / \[ 2 (r0-rc)^2\]. + +The following coefficients must be defined for each bond type via the +"bond_coeff"_bond_coeff.html command as in the example above, or in +the data file or restart files read by the "read_data"_read_data.html +or "read_restart"_read_restart.html commands: + +Umin (energy) :ul +r0 (distance) :ul +rc (distance) :ul + +[Restrictions:] + +This bond style can only be used if LAMMPS was built with the +"user-misc" package. See the "Making LAMMPS"_Section_start.html#2_3 +section for more info on packages. + +[Related commands:] + +"bond_coeff"_bond_coeff.html, "delete_bonds"_delete_bonds.html, +"bond_harmonic"_bond_harmonic.html + +[Default:] none diff --git a/doc/bond_harmonic_shift_cut.html b/doc/bond_harmonic_shift_cut.html new file mode 100644 index 0000000000..04086f9702 --- /dev/null +++ b/doc/bond_harmonic_shift_cut.html @@ -0,0 +1,57 @@ + +Syntax: +
+bond_style harmonic/shift/cut ++
Examples: +
+bond_style harmonic/shift/cut +bond_coeff 5 10.0 0.5 1.0 ++
Description: +
+The harmonic/shift/cut bond style is a shifted harmonic bond that +uses the potential +
+
+where r0 is the equilibrium bond distance, and rc the critical distance. +The bond potential is zero for distances r > rc. The potential is -Umin +at r0 and zero at rc. The spring constant is k = Umin / [ 2 (r0-rc)^2]. +
+The following coefficients must be defined for each bond type via the +bond_coeff command as in the example above, or in +the data file or restart files read by the read_data +or read_restart commands: +
+Restrictions: +
+This bond style can only be used if LAMMPS was built with the +"user-misc" package. See the Making LAMMPS +section for more info on packages. +
+Related commands: +
+bond_coeff, delete_bonds, +bond_harmonic, +bond_harmonicshift +
+Default: none +
+ diff --git a/doc/bond_harmonic_shift_cut.txt b/doc/bond_harmonic_shift_cut.txt new file mode 100644 index 0000000000..e6ff765109 --- /dev/null +++ b/doc/bond_harmonic_shift_cut.txt @@ -0,0 +1,52 @@ +"LAMMPS WWW Site"_lws - "LAMMPS Documentation"_ld - "LAMMPS Commands"_lc :c + +:link(lws,http://lammps.sandia.gov) +:link(ld,Manual.html) +:link(lc,Section_commands.html#comm) + +:line + +bond_style harmonic/shift/cut command :h3 + +[Syntax:] + +bond_style harmonic/shift/cut :pre + +[Examples:] + +bond_style harmonic/shift/cut +bond_coeff 5 10.0 0.5 1.0 :pre + +[Description:] + +The {harmonic/shift/cut} bond style is a shifted harmonic bond that +uses the potential + +:c,image(Eqs/bond_harmonic_shift_cut.jpg) + +where r0 is the equilibrium bond distance, and rc the critical distance. +The bond potential is zero for distances r > rc. The potential is -Umin +at r0 and zero at rc. The spring constant is k = Umin / \[ 2 (r0-rc)^2\]. + +The following coefficients must be defined for each bond type via the +"bond_coeff"_bond_coeff.html command as in the example above, or in +the data file or restart files read by the "read_data"_read_data.html +or "read_restart"_read_restart.html commands: + +Umin (energy) +r0 (distance) +rc (distance) :ul + +[Restrictions:] + +This bond style can only be used if LAMMPS was built with the +"user-misc" package. See the "Making LAMMPS"_Section_start.html#2_3 +section for more info on packages. + +[Related commands:] + +"bond_coeff"_bond_coeff.html, "delete_bonds"_delete_bonds.html, +"bond_harmonic"_bond_harmonic.html, +"bond_harmonicshift"_bond_harmonicshift.html + +[Default:] none diff --git a/doc/dihedral_cosine_shift_exp.html b/doc/dihedral_cosine_shift_exp.html new file mode 100644 index 0000000000..73f830c3b2 --- /dev/null +++ b/doc/dihedral_cosine_shift_exp.html @@ -0,0 +1,65 @@ + +Syntax: +
+dihedral_style cosine/shift/exp ++
Examples: +
+dihedral_style cosine/shift/exp +dihedral_coeff 1 10.0 45.0 2.0 ++
Description: +
+The cosine/shift/exp dihedral style uses the potential +
+
+where Umin, theta, and a are defined for each dihedral type. +
+The potential is bounded between [-Umin:0] and the minimum is located +at the angle theta0. The a parameter can be both positive or negative +and is used to control the spring constant at the equilibrium. +
+The spring constant is given by k=a exp(a) Umin/ [2 (Exp(a)-1)]. +For a>3 k/Umin = a/2 to better than 5% relative error. For negative +values of the a parameter, the spring constant is essentially zero, +and anharmonic terms takes over. The potential is furthermore well +behaved in the limit a->0, where it has been implemented to linear +order in a for a < 0.001. +
+The following coefficients must be defined for each dihedral type via +the dihedral_coeff command as in the example +above, or in the data file or restart files read by the +read_data or read_restart +commands: +
+Restrictions: +
+This dihedral style can only be used if LAMMPS was built with the +"user-misc" package. See the Making LAMMPS +section for more info on packages. +
+Related commands: +
+dihedral_coeff, +angle_cosineshiftexp +
+Default: none +
+ diff --git a/doc/dihedral_cosine_shift_exp.txt b/doc/dihedral_cosine_shift_exp.txt new file mode 100644 index 0000000000..ee01c29e9d --- /dev/null +++ b/doc/dihedral_cosine_shift_exp.txt @@ -0,0 +1,60 @@ +"LAMMPS WWW Site"_lws - "LAMMPS Documentation"_ld - "LAMMPS Commands"_lc :c + +:link(lws,http://lammps.sandia.gov) +:link(ld,Manual.html) +:link(lc,Section_commands.html#comm) + +:line + +dihedral_style cosine/shift/exp command :h3 + +[Syntax:] + +dihedral_style cosine/shift/exp :pre + +[Examples:] + +dihedral_style cosine/shift/exp +dihedral_coeff 1 10.0 45.0 2.0 :pre + +[Description:] + +The {cosine/shift/exp} dihedral style uses the potential + +:c,image(Eqs/dihedral_cosine_shift_exp.jpg) + +where Umin, theta, and a are defined for each dihedral type. + +The potential is bounded between \[-Umin:0\] and the minimum is located +at the angle theta0. The a parameter can be both positive or negative +and is used to control the spring constant at the equilibrium. + +The spring constant is given by k=a exp(a) Umin/ \[2 (Exp(a)-1)\]. +For a>3 k/Umin = a/2 to better than 5% relative error. For negative +values of the a parameter, the spring constant is essentially zero, +and anharmonic terms takes over. The potential is furthermore well +behaved in the limit a->0, where it has been implemented to linear +order in a for a < 0.001. + +The following coefficients must be defined for each dihedral type via +the "dihedral_coeff"_dihedral_coeff.html command as in the example +above, or in the data file or restart files read by the +"read_data"_read_data.html or "read_restart"_read_restart.html +commands: + +umin (energy) +theta (angle) +A (real number) :ul + +[Restrictions:] + +This dihedral style can only be used if LAMMPS was built with the +"user-misc" package. See the "Making LAMMPS"_Section_start.html#2_3 +section for more info on packages. + +[Related commands:] + +"dihedral_coeff"_dihedral_coeff.html, +"angle_cosineshiftexp"_angle_cosineshiftexp.html + +[Default:] none