Fig. 3: Structure and population of dipolar defects.
From: Deuteration removes quantum dipolar defects from KDP crystals
a Schematic representation of the rules for the classification of each KDP/DKDP replica. Each P–O–H (yellow–red–blue) structure can be donor (left) or acceptor (right) type. The gray sphere indicates the ___location of the electronic centroid. b The joint probability distribution of α and rO→H for KDP and DKDP, respectively, in the ferroelectric (T = Tc − 10 K) and the paraelectric phase (insets, T = Tc + 20 K). The vertical gray dashed line shows r* = 1.25 Å. c Percent population of the different classes of KDP/DKDP units vs temperature. The vertical gray dashed line shows Tc. d RDF of the Takagi defects in KDP at 50 K. The distance r between the defects is the spatial separation of the respective P ions.
