correct typo in formula

doc/src/Eqs/pair_tersoff_mod_c.tex

@@ -4,7 +4,7 @@
 \begin{document}
 
 \begin{eqnarray*}
-  V_{ij}  & =  & f_C(r_{ij}) \left[ f_R(r_{ij}) + b_{ij} f_A(r_{ij} + c_0) \right]
+  V_{ij}  & =  & f_C(r_{ij}) \left[ f_R(r_{ij}) + b_{ij} f_A(r_{ij}) + c_0 \right]
 \end{eqnarray*}
 
 \end{document}

doc/src/pair_tersoff_mod.txt

@@ -42,6 +42,7 @@ The summations in the formula are over all neighbors J and K of atom I
 within a cutoff distance = R + D.
 The {tersoff/mod/c} style differs from {tersoff/mod} only in the
 formulation of the V_ij term, where it contains an additional c0 term.
+
 :c,image(Eqs/pair_tersoff_mod_c.jpg)