The use of Sites in Symmorphic Space Groups for Identification of Possible Ferroelectric Phases

We suggest defining two types of sites in the space groups and it is shown that symmorphic space groups sites of type Ⅱ whose coordinates consist of only coordinate variables and zeros correspond to possible ferroelectric phases. By collecting the sites of type Ⅱ in the symmorphic space groups from International Tables for X-ray crystallography 88 possible para-ferroelectric phase transitions are obtained.