Simulations of a capped alanine dipeptide in spherical geometry were set up by replacing eight central water molecules in the pre-equilibrated cubic box. The C α atom of the dipeptide was harmonically restrained to the box center with a force constant of 10 5 kJ mol -1 nm -2 . The system was equilibrated for 0.1 ns. Sampling was then carried out for 100 ns with configurations written out every 500 steps. Simulations were carried out either without or with the correction potentials, which were constructed for the pure-water system.