Sea can cause individual (unexpected) rogue waves much higher than normal. Most waves are less than high and it is not unusual for strong storms to double or triple that height; offshore construction such as wind farms and oil platforms use metocean statistics from measurements in computing the wave forces (due to for instance the hundred-year wave) they are designed against. Rogue waves, however, have been documented at heights above . The top of a wave is known as the crest, the lowest point between waves is the trough and the distance between the crests is the wavelength. The wave is
Madelung constant Madelung constant allows for the calculation of the electric potential "V" of all ions of the lattice felt by the ion at position "r" where "r" =|"r" - "r"| is the distance between the "i"th and the "j"th ion. In addition, If the distances "r" are normalized to the nearest neighbor distance "r" the potential may be written with formula_3 being the (dimensionless) Madelung constant of the "i"th ion The electrostatic energy of the ion at site formula_5 then is the product of its charge with the potential acting at its site There occur as many Madelung constants formula_3 in