A method for performing a molecular dynamics simulation for determining the solvent accessible surface area of a molecule with respect to atomic coordinates, the molecule comprising a plurality of atoms, a sphere being assigned to each atom, and each sphere comprising a radius and a center position. The retainer may be biased towards the riving knife. The method also typically includes determining a single most recently used set from among the stored plurality of most recently used items viewed for at least one data object designated as able to be accessed by a user at a mobile device. The two-wire cable provides power from the controller and power supply unit to each of the irrigation control units, it transmits schedules of instructions to the irrigation control units through the two-wire cable, and it receives the irrigation parameters from the irrigation control units through the two-wire cable.