A robust and fast method is presented that provides a simple real-space convergent solution for identifying equilibrium orientations of crystallization H₂O molecules in ionic crystals, on the basis of zero net torque. The predicted H₂O orientations constrained by rotational equilibrium are compared with neutron scattering experiments and/or ab initio density functional theory (DFT) calculations. The comparison shows that predicted and observed H₂O orientations are consistent, demonstrating the reliability of the reported torque method. Moreover, the rotational equilibrium conditions predict an alternative, not previously observed, H₂O orientation in kernite [Na₂B₄O₆(OH)₂·3H₂O], and this may explain anomalously large displacement parameters that have been reported for this mineral. Complementary DFT computations corroborate that the two orientations are geometrically distinct and energetically near degenerate.