Update README.md

Author: simongravelle

README.md

@@ -14,9 +14,8 @@ progressively increased for [Pulling on a carbon nanotube](https://lammpstutoria
 [Polymer in water](https://lammpstutorials.github.io/sphinx/build/html/tutorials/level2/polymer-in-water.html), 
 [Nanosheared electrolyte](https://lammpstutorials.github.io/sphinx/build/html/tutorials/level2/nanosheared-electrolyte.html),
 and [Reactive silicon dioxide](https://lammpstutorials.github.io/sphinx/build/html/tutorials/level3/reactive-silicon-dioxide.html). 
-Finally,
-[Water adsorption in silica](https://lammpstutorials.github.io/sphinx/build/html/tutorials/level3/water-adsorption-in-silica.html) and
-[Free energy [calculation](https://lammpstutorials.github.io/sphinx/build/html/tutorials/level3/free-energy-calculation.html) use some more advanced simulation methods that are commonly used when studying soft matter systems, respectively grand canonical Monte Carlo simulations and a free energy method named umbrella sampling.
+Finally, [Water adsorption in silica](https://lammpstutorials.github.io/sphinx/build/html/tutorials/level3/water-adsorption-in-silica.html) and
+[Free energy calculation](https://lammpstutorials.github.io/sphinx/build/html/tutorials/level3/free-energy-calculation.html) use some more advanced simulation methods that are commonly used when studying soft matter systems, respectively grand canonical Monte Carlo simulations and a free energy method named umbrella sampling.
 
 <p float="left">
     <a href="https://lammpstutorials.github.io/sphinx/build/html/tutorials/level1/lennard-jones-fluid.html">