Ionic order Ionian dialect was spoken. The Ionic order column was being practiced in mainland Greece in the 5th century BC. It was most popular in the Archaic Period (750–480 BC) in Ionia. The first of the great Ionic temples was the Temple of Hera on Samos, built about 570–560 BC by the architect Rhoikos. It stood for only a decade before it was leveled by an earthquake. A longer-lasting 6th century Ionic temple was the Temple of Artemis at Ephesus, one of the Seven Wonders of the Ancient World. The Parthenon, although it conforms mainly to the Doric order, also has
Ionic radius radii. The relation between soft-sphere ionic radii, formula_2 and formula_3, and formula_1, is given by formula_5, where formula_6 is an exponent that varies with the type of crystal structure. In the hard-sphere model, formula_6 would be 1, giving formula_8. In the soft-sphere model, formula_6 has a value between 1 and 2. For example, for crystals of group 1 halides with the sodium chloride structure, a value of 1.6667 gives good agreement with experiment. Some soft-sphere ionic radii are in the table. These radii are larger than the crystal radii given above (Li, 90 pm; Cl, 167 pm). Inter-ionic separations calculated