One- and three-dimensional antiferroelectric ordering in Pr<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">Cl</mml:mi></mml:mrow><mml:mrow><mml:mn>3</mml:mn></mml:mrow></mml:msub></mml:mrow></mml:math>

Electric-susceptibility and specific-heat measurement in Pr${\mathrm{Cl}}_{3}$ show that electric dipole ordering occurs at low temperatures. One-dimensional ordering is observed above 0.4 K and is well described by the linear-chain $\mathrm{XY}$ model. Three-dimensional antiferroelectric ordering occurs at 0.4 K. The electric dipole moments are developed by the non-Kramers-doublet ground states of the praseodymium ions. The nearest-neighbor electric dipole-dipole interaction calculated from the measured dipole moment is of the correct sign and of approximately the correct magnitude to account for the nearest-neighbor interaction deduced from the fitting of the specific heat to the one-dimensional $\mathrm{XY}$ model. The small change in the magnitude of the specific-heat anomally (\ensuremath{\sim} 15%) and the small shift of the three-dimensional transition temperature (\ensuremath{\sim} 5%) when a magnetic field of 2.2 T was applied provides further evidence that the ordering in Pr${\mathrm{Cl}}_{3}$ is of nonmagnetic origin.

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