pair_style lj/cut/tip4p/cut 1 2 7 8 0.15 12.0 +pair_style lj/cut/tip4p/cut 1 2 7 8 0.15 12.0 10.0 +pair_coeff * * 100.0 3.0 +pair_coeff 1 1 100.0 3.5 9.0 +
pair_style lj/cut/tip4p/long 1 2 7 8 0.15 12.0 pair_style lj/cut/tip4p/long 1 2 7 8 0.15 12.0 10.0 pair_coeff * * 100.0 3.0 @@ -195,14 +200,15 @@ specified for this style means that pairwise interactions within this distance are computed directly; interactions outside that distance are computed in reciprocal space. -Style lj/cut/tip4p/long implements the TIP4P water model of -(Jorgensen), which introduces a massless site located a -short distance away from the oxygen atom along the bisector of the HOH -angle. The atomic types of the oxygen and hydrogen atoms, the bond -and angle types for OH and HOH interactions, and the distance to the -massless charge site are specified as pair_style arguments. Style -lj/cut/tip4p/cut is similar to lj/cut/tip4p/long, only it uses a -cutoff for Coulomb interactions. +
Styles lj/cut/tip4p/cut and lj/cut/tip4p/long implement the TIP4P +water model of (Jorgensen), which introduces a massless +site located a short distance away from the oxygen atom along the +bisector of the HOH angle. The atomic types of the oxygen and +hydrogen atoms, the bond and angle types for OH and HOH interactions, +and the distance to the massless charge site are specified as +pair_style arguments. Style lj/cut/tip4p/cut uses a cutoff for +Coulomb interactions; style lj/cut/tip4p/long is for use with a +long-range Coulombic solver (Ewald or PPPM).
IMPORTANT NOTE: For each TIP4P water molecule in your system, the atom IDs for the O and 2 H atoms must be consecutive, with the O atom @@ -211,14 +217,15 @@ with each O atom. For example, if the atom ID of an O atom in a TIP4P water molecule is 500, then its 2 H atoms must have IDs 501 and 502.
See the howto section for more -information on how to use the TIP4P pair style. Note that the -neighobr list cutoff for Coulomb interactions is effectively extended -by a distance 2*qdist when using the TIP4P pair style, to account for -the offset distance of the fictitious charges on O atoms in water -molecules. Thus it is typically best in an efficiency sense to use a -LJ cutoff >= Coulomb cutoff + 2*qdist, to shrink the size of the -neighbor list. This leads to slightly larger cost for the long-range -calculation, so you can test the trade-off for your model. +information on how to use the TIP4P pair styles and lists of +parameters to set. Note that the neighobr list cutoff for Coulomb +interactions is effectively extended by a distance 2*qdist when using +the TIP4P pair style, to account for the offset distance of the +fictitious charges on O atoms in water molecules. Thus it is +typically best in an efficiency sense to use a LJ cutoff >= Coulomb +cutoff + 2*qdist, to shrink the size of the neighbor list. This leads +to slightly larger cost for the long-range calculation, so you can +test the trade-off for your model.
For all of the lj/cut pair styles, the following coefficients must be defined for each pair of atoms types via the @@ -244,10 +251,11 @@ are specified, they are used as the LJ and Coulombic cutoffs for this type pair. You cannot specify 2 cutoffs for style lj/cut, since it has no Coulombic terms.
-For lj/cut/coul/long and lj/cut/coul/msm and lj/cut/tip4p/long -only the LJ cutoff can be specified since a Coulombic cutoff cannot be -specified for an individual I,J type pair. All type pairs use the -same global Coulombic cutoff specified in the pair_style command. +
For lj/cut/coul/long and lj/cut/coul/msm and lj/cut/tip4p/cut +and lj/cut/tip4p/long only the LJ cutoff can be specified since a +Coulombic cutoff cannot be specified for an individual I,J type pair. +All type pairs use the same global Coulombic cutoff specified in the +pair_style command.
diff --git a/doc/pair_lj.txt b/doc/pair_lj.txt index 3b76d70129..418ed9415c 100644 --- a/doc/pair_lj.txt +++ b/doc/pair_lj.txt @@ -105,6 +105,11 @@ pair_style lj/cut/coul/msm 10.0 8.0 pair_coeff * * 100.0 3.0 pair_coeff 1 1 100.0 3.5 9.0 :pre +pair_style lj/cut/tip4p/cut 1 2 7 8 0.15 12.0 +pair_style lj/cut/tip4p/cut 1 2 7 8 0.15 12.0 10.0 +pair_coeff * * 100.0 3.0 +pair_coeff 1 1 100.0 3.5 9.0 :pre + pair_style lj/cut/tip4p/long 1 2 7 8 0.15 12.0 pair_style lj/cut/tip4p/long 1 2 7 8 0.15 12.0 10.0 pair_coeff * * 100.0 3.0 @@ -164,14 +169,15 @@ specified for this style means that pairwise interactions within this distance are computed directly; interactions outside that distance are computed in reciprocal space. -Style {lj/cut/tip4p/long} implements the TIP4P water model of -"(Jorgensen)"_#Jorgensen, which introduces a massless site located a -short distance away from the oxygen atom along the bisector of the HOH -angle. The atomic types of the oxygen and hydrogen atoms, the bond -and angle types for OH and HOH interactions, and the distance to the -massless charge site are specified as pair_style arguments. Style -{lj/cut/tip4p/cut} is similar to {lj/cut/tip4p/long}, only it uses a -cutoff for Coulomb interactions. +Styles {lj/cut/tip4p/cut} and {lj/cut/tip4p/long} implement the TIP4P +water model of "(Jorgensen)"_#Jorgensen, which introduces a massless +site located a short distance away from the oxygen atom along the +bisector of the HOH angle. The atomic types of the oxygen and +hydrogen atoms, the bond and angle types for OH and HOH interactions, +and the distance to the massless charge site are specified as +pair_style arguments. Style {lj/cut/tip4p/cut} uses a cutoff for +Coulomb interactions; style {lj/cut/tip4p/long} is for use with a +long-range Coulombic solver (Ewald or PPPM). IMPORTANT NOTE: For each TIP4P water molecule in your system, the atom IDs for the O and 2 H atoms must be consecutive, with the O atom @@ -180,14 +186,15 @@ with each O atom. For example, if the atom ID of an O atom in a TIP4P water molecule is 500, then its 2 H atoms must have IDs 501 and 502. See the "howto section"_Section_howto.html#howto_8 for more -information on how to use the TIP4P pair style. Note that the -neighobr list cutoff for Coulomb interactions is effectively extended -by a distance 2*qdist when using the TIP4P pair style, to account for -the offset distance of the fictitious charges on O atoms in water -molecules. Thus it is typically best in an efficiency sense to use a -LJ cutoff >= Coulomb cutoff + 2*qdist, to shrink the size of the -neighbor list. This leads to slightly larger cost for the long-range -calculation, so you can test the trade-off for your model. +information on how to use the TIP4P pair styles and lists of +parameters to set. Note that the neighobr list cutoff for Coulomb +interactions is effectively extended by a distance 2*qdist when using +the TIP4P pair style, to account for the offset distance of the +fictitious charges on O atoms in water molecules. Thus it is +typically best in an efficiency sense to use a LJ cutoff >= Coulomb +cutoff + 2*qdist, to shrink the size of the neighbor list. This leads +to slightly larger cost for the long-range calculation, so you can +test the trade-off for your model. For all of the {lj/cut} pair styles, the following coefficients must be defined for each pair of atoms types via the @@ -213,10 +220,11 @@ are specified, they are used as the LJ and Coulombic cutoffs for this type pair. You cannot specify 2 cutoffs for style {lj/cut}, since it has no Coulombic terms. -For {lj/cut/coul/long} and {lj/cut/coul/msm} and {lj/cut/tip4p/long} -only the LJ cutoff can be specified since a Coulombic cutoff cannot be -specified for an individual I,J type pair. All type pairs use the -same global Coulombic cutoff specified in the pair_style command. +For {lj/cut/coul/long} and {lj/cut/coul/msm} and {lj/cut/tip4p/cut} +and {lj/cut/tip4p/long} only the LJ cutoff can be specified since a +Coulombic cutoff cannot be specified for an individual I,J type pair. +All type pairs use the same global Coulombic cutoff specified in the +pair_style command. :line