diff --git a/doc/src/pair_coul.rst b/doc/src/pair_coul.rst index 4e0793467b..f22bc974b0 100644 --- a/doc/src/pair_coul.rst +++ b/doc/src/pair_coul.rst @@ -174,11 +174,11 @@ shifted force model described in :ref:`Fennell `, given by: E = q_iq_j \left[ \frac{\mbox{erfc} (\alpha r)}{r} - \frac{\mbox{erfc} (\alpha r_c)}{r_c} + \left( \frac{\mbox{erfc} (\alpha r_c)}{r_c^2} + \frac{2\alpha}{\sqrt{\pi}}\frac{\exp (-\alpha^2 r^2_c)}{r_c} \right)(r-r_c) \right] \qquad r < r_c -where :math:`\alpha` is the damping parameter and erfc() is the -complementary error-function. The potential corrects issues in the -Wolf model (described below) to provide consistent forces and energies -(the Wolf potential is not differentiable at the cutoff) and smooth -decay to zero. +where :math:`\alpha` is the damping parameter and *erfc()* is the +complementary error-function. The potential corrects issues in the Wolf +model (described below) to provide consistent forces and energies (the +Wolf potential is not differentiable at the cutoff) and smooth decay to +zero. ---------- @@ -192,30 +192,32 @@ summation method, described in :ref:`Wolf `, given by: \frac{1}{2} \sum_{j \neq i} \frac{q_i q_j {\rm erf}(\alpha r_{ij})}{r_{ij}} \qquad r < r_c -where :math:`\alpha` is the damping parameter, and erc() and erfc() are -error-function and complementary error-function terms. This potential -is essentially a short-range, spherically-truncated, +where :math:`\alpha` is the damping parameter, and *erf()* and *erfc()* +are error-function and complementary error-function terms. This +potential is essentially a short-range, spherically-truncated, charge-neutralized, shifted, pairwise *1/r* summation. With a manipulation of adding and subtracting a self term (for i = j) to the -first and second term on the right-hand-side, respectively, and a -small enough :math:`\alpha` damping parameter, the second term shrinks and -the potential becomes a rapidly-converging real-space summation. With -a long enough cutoff and small enough :math:`\alpha` parameter, the energy and -forces calculated by the Wolf summation method approach those of the +first and second term on the right-hand-side, respectively, and a small +enough :math:`\alpha` damping parameter, the second term shrinks and the +potential becomes a rapidly-converging real-space summation. With a +long enough cutoff and small enough :math:`\alpha` parameter, the energy +and forces calculated by the Wolf summation method approach those of the Ewald sum. So it is a means of getting effective long-range interactions with a short-range potential. ---------- -Style *coul/streitz* is the Coulomb pair interaction defined as part -of the Streitz-Mintmire potential, as described in :ref:`this paper `, in which charge distribution about an atom is modeled -as a Slater 1\ *s* orbital. More details can be found in the referenced +Style *coul/streitz* is the Coulomb pair interaction defined as part of +the Streitz-Mintmire potential, as described in :ref:`this paper +`, in which charge distribution about an atom is modeled as a +Slater 1\ *s* orbital. More details can be found in the referenced paper. To fully reproduce the published Streitz-Mintmire potential, -which is a variable charge potential, style *coul/streitz* must be -used with :doc:`pair_style eam/alloy ` (or some other -short-range potential that has been parameterized appropriately) via -the :doc:`pair_style hybrid/overlay ` command. Likewise, -charge equilibration must be performed via the :doc:`fix qeq/slater ` command. For example: +which is a variable charge potential, style *coul/streitz* must be used +with :doc:`pair_style eam/alloy ` (or some other short-range +potential that has been parameterized appropriately) via the +:doc:`pair_style hybrid/overlay ` command. Likewise, +charge equilibration must be performed via the :doc:`fix qeq/slater +` command. For example: .. code-block:: LAMMPS diff --git a/doc/utils/sphinx-config/false_positives.txt b/doc/utils/sphinx-config/false_positives.txt index 6193d52046..ca233e0b96 100644 --- a/doc/utils/sphinx-config/false_positives.txt +++ b/doc/utils/sphinx-config/false_positives.txt @@ -977,7 +977,6 @@ equilization equipartitioning eradius erate -erc Ercolessi Erdmann erf