Update pair_beck docs

doc/src/Eqs/pair_beck.tex

@@ -1,11 +0,0 @@
-\documentstyle[12pt]{article}
-
-\begin{document}
-
-$$
-E\left(r\right) = A \exp\left[-\alpha r - \beta r^6\right] -
-\frac{B}{\left(r^2+a^2\right)^3} \left(1+\frac{2.709+3a^2}{r^2+a^2}\right)
-   \qquad r < R_c 
-$$
-
-\end{document}

doc/src/pair_beck.rst

@@ -1,19 +1,19 @@
-.. index:: pair\_style beck
+.. index:: pair_style beck
 
-pair\_style beck command
-========================
+pair_style beck command
+=======================
 
-pair\_style beck/gpu command
-============================
+pair_style beck/gpu command
+===========================
 
-pair\_style beck/omp command
-============================
+pair_style beck/omp command
+===========================
 
 Syntax
 """"""
 
 
-.. parsed-literal::
+.. code-block:: LAMMPS
 
    pair_style beck Rc
 
@@ -23,10 +23,10 @@ Examples
 """"""""
 
 
-.. parsed-literal::
+.. code-block:: LAMMPS
 
    pair_style beck 8.0
-   pair_coeff \* \* 399.671876712 0.0000867636112694 0.675 4.390 0.0003746
+   pair_coeff * * 399.671876712 0.0000867636112694 0.675 4.390 0.0003746
    pair_coeff 1 1 399.671876712 0.0000867636112694 0.675 4.390 0.0003746 6.0
 
 Description
@@ -36,8 +36,10 @@ Style *beck* computes interactions based on the potential by
 :ref:`(Beck) <Beck>`, originally designed for simulation of Helium.  It
 includes truncation at a cutoff distance Rc.
 
-.. image:: Eqs/pair_beck.jpg
-   :align: center
+.. math::
+
+   E(r) &= A \exp\left[-\alpha r - \beta r^6\right] - \frac{B}{\left(r^2+a^2\right)^3} \left(1+\frac{2.709+3a^2}{r^2+a^2}\right) \qquad r < R_c \\
+
 
 The following coefficients must be defined for each pair of atoms
 types via the :doc:`pair_coeff <pair_coeff>` command as in the examples
@@ -45,15 +47,15 @@ above, or in the data file or restart files read by the
 :doc:`read_data <read_data>` or :doc:`read_restart <read_restart>`
 commands.
 
-* A (energy units)
-* B (energy-distance\^6 units)
-* a (distance units)
-* alpha (1/distance units)
-* beta  (1/distance\^6 units)
+* :math:`A` (energy units)
+* :math:`B` (energy-distance\^6 units)
+* :math:`a` (distance units)
+* :math:`\alpha` (1/distance units)
+* :math:`\beta`  (1/distance\^6 units)
 * cutoff (distance units)
 
 The last coefficient is optional.  If not specified, the global cutoff
-Rc is used.
+:math:`R_c` is used.
 
 
 ----------
@@ -108,7 +110,7 @@ This pair style can only be used via the *pair* keyword of the
 
 Restrictions
 """"""""""""
- none
+none
 
 Related commands
 """"""""""""""""