Doric order proportions. It is suggested that these proportions give the Doric columns a masculine appearance, whereas the more slender Ionic columns appear to represent a more feminine look. This sense of masculinity and femininity was often used to determine which type of column would be used for a particular structure. The most influential, and perhaps the earliest, use of the Doric in Renaissance architecture was in the circular "Tempietto" by Donato Bramante (1502 or later), in the courtyard of San Pietro in Montorio, Rome. Before Greek Revival architecture grew, initially in England, in the 18th century, the Greek or elaborated Roman
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