At T = 0, all energy of thermal motion has been quenched, and in a perfect crystal all
the atoms or ions are in a regular, uniform array. The localization of matter and the
absence of thermal motion suggest that such materials also have zero entropy. This
conclusion is consistent with the molecular interpretation of entropy, because S = 0 if
there is only one way of arranging the molecules and only one microstate is accessible
(all molecules occupy the ground state).