Experimental data and the principles of quantum mechanics suggest that a crystal is a condensate of "wavicles" enclosed in a box, where "wavicle" denotes the indefinite wave-particle status of the microscopic constituents. When it is not perturbed the crystal is in a classicallike state. The wavefunction, the internal energy and the entropy are all of them equal to zero. The thermodynamic temperature is indefinite. Perturbations via energy-and/or momentumtransfer reveal quantum effects. The temperature laws for the heat capacities of some hydrogenbonded crystals are rationalized with superposition states depending on the quantum temperature which is crystal-dependent. Heat-transfer is a coherent anentropic process. Apart from energy conservation, the other laws of thermodynamics are irrelevant.