One aspect of the present invention relates to ligands for transition metals. The magnetic positioning system having a magnet that provides sufficient magnetic force, but does not have enough electrical conductivity to overheat in the presence of the anticipated electromagnetic field. The central receiving seat is embedded in the groove and has an upper and a lower positioning hole, so that the hand pull-bar can be positioned in the upper or the lower positioning hole in its stretching and contracting stroke. Circuitry connected to the current transformers and line voltage connections meter the energy over the electrical wires. The recess has a bottom surface and a side surface adjacent thereto. A sharing audits and history feature allows a user to view who has looked at their calendar and what calendar information has been viewed.