diff --git a/doc/src/Eqs/angle_mm3.jpg b/doc/src/Eqs/angle_mm3.jpg
deleted file mode 100644
index 5b9f3e34f0..0000000000
Binary files a/doc/src/Eqs/angle_mm3.jpg and /dev/null differ
diff --git a/doc/src/Eqs/angle_mm3.tex b/doc/src/Eqs/angle_mm3.tex
deleted file mode 100644
index e2d96f2d69..0000000000
--- a/doc/src/Eqs/angle_mm3.tex
+++ /dev/null
@@ -1,9 +0,0 @@
-\documentclass[12pt]{article}
-
-\begin{document}
-\thispagestyle{empty}
-$$
-  E = K (\theta - \theta_0)^2 \left[ 1 - 0.014(\theta - \theta_0) + 5.6(10)^{-5} (\theta - \theta_0)^2 - 7.0(10)^{-7} (\theta - \theta_0)^3 + 9(10)^{-10} (\theta - \theta_0)^4 \right]
-$$
-
-\end{document}
diff --git a/doc/src/angle_mm3.rst b/doc/src/angle_mm3.rst
index 50786363b2..7cf7f9e720 100644
--- a/doc/src/angle_mm3.rst
+++ b/doc/src/angle_mm3.rst
@@ -1,13 +1,13 @@
-.. index:: angle\_style mm3
+.. index:: angle_style mm3
 
-angle\_style mm3 command
-========================
+angle_style mm3 command
+=======================
 
 Syntax
 """"""
 
 
-.. parsed-literal::
+.. code-block:: LAMMPS
 
    angle_style mm3
 
@@ -15,7 +15,7 @@ Examples
 """"""""
 
 
-.. parsed-literal::
+.. code-block:: LAMMPS
 
    angle_style mm3
    angle_coeff 1 100.0 107.0
@@ -26,23 +26,25 @@ Description
 The *mm3* angle style uses the potential that is anharmonic in the angle
 as defined in :ref:`(Allinger) <mm3-allinger1989>`
 
-.. image:: Eqs/angle_mm3.jpg
-   :align: center
+.. math::
 
-where theta0 is the equilibrium value of the angle, and K is a
-prefactor. The anharmonic prefactors have units deg\^(-n), for example
--0.014 deg\^(-1), 5.6(10)\^(-5) deg\^(-2), ...
+   E = K (\theta - \theta_0)^2 \left[ 1 - 0.014(\theta - \theta_0) + 5.6(10)^{-5} (\theta - \theta_0)^2 - 7.0(10)^{-7} (\theta - \theta_0)^3 + 9(10)^{-10} (\theta - \theta_0)^4 \right]
+
+
+where :math:`\theta_0` is the equilibrium value of the angle, and :math:`K` is a
+prefactor. The anharmonic prefactors have units :math:`\deg^{-n}`, for example
+:math:`-0.014 \deg^{-1}`, :math:`5.6 \cdot 10^{-5} \deg^{-2}`, ...
 
 The following coefficients must be defined for each angle type via the
 :doc:`angle\_coeff <angle_coeff>` command as in the example above, or in
 the data file or restart files read by the :doc:`read\_data <read_data>`
 or :doc:`read\_restart <read_restart>` commands:
 
-* K (energy/radian\^2)
-* theta0 (degrees)
+* :math:`K` (energy/radian\^2)
+* :math:`\theta_0` (degrees)
 
-Theta0 is specified in degrees, but LAMMPS converts it to radians
-internally; hence the units of K are in energy/radian\^2.
+:math:`\theta_0` is specified in degrees, but LAMMPS converts it to radians
+internally; hence the units of :math:`K` are in energy/radian\^2.
 
 Restrictions
 """"""""""""
@@ -58,12 +60,3 @@ Related commands
 :doc:`angle\_coeff <angle_coeff>`
 
 **Default:** none
-
-
-----------
-
-
-
-.. _lws: http://lammps.sandia.gov
-.. _ld: Manual.html
-.. _lc: Commands_all.html
diff --git a/doc/txt/angle_mm3.txt b/doc/txt/angle_mm3.txt
deleted file mode 100644
index 9ae032c4ff..0000000000
--- a/doc/txt/angle_mm3.txt
+++ /dev/null
@@ -1,55 +0,0 @@
-"LAMMPS WWW Site"_lws - "LAMMPS Documentation"_ld - "LAMMPS Commands"_lc :c
-
-:link(lws,http://lammps.sandia.gov)
-:link(ld,Manual.html)
-:link(lc,Commands_all.html)
-
-:line
-
-angle_style mm3 command :h3
-
-[Syntax:]
-
-angle_style mm3 :pre
-
-[Examples:]
-
-angle_style mm3
-angle_coeff 1 100.0 107.0 :pre
-
-[Description:]
-
-The {mm3} angle style uses the potential that is anharmonic in the angle
-as defined in "(Allinger)"_#mm3-allinger1989
-
-:c,image(Eqs/angle_mm3.jpg)
-
-where theta0 is the equilibrium value of the angle, and K is a
-prefactor. The anharmonic prefactors have units deg^(-n), for example
--0.014 deg^(-1), 5.6(10)^(-5) deg^(-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:
-
-K (energy/radian^2)
-theta0 (degrees) :ul
-
-Theta0 is specified in degrees, but LAMMPS converts it to radians
-internally; hence the units of K are in energy/radian^2.
-
-[Restrictions:]
-
-This angle style can only be used if LAMMPS was built with the
-USER_YAFF package.  See the "Build package"_Build_package.html doc
-page for more info.
-
-[Related commands:]
-
-"angle_coeff"_angle_coeff.html
-
-[Default:] none
-
-:line
-