Basic relationships concerning thermodynamics of crystalline phases and the process of their formation, as well as energetics of intermolecular interactions in these, were invoked and discussed from the point of view of their application in studies of stability, features and behaviour of solid systems. Further, electrostatic, dispersive and repulsive contributions to the crystal lattice energy of 25 hydrohalides of aminoacids were calculated assuming that each atom of the basic stoichiometric unit interacts with all atoms from surroundings. Energy of electrostatic interactions was obtained assuming 1+ and 1- charges on cation and anion, respectively, and using atomic partial charges resulting from Mulliken population analysis or fitted so as to reproduce molecular electrostatic potential (MEP) around molecules, determined on ab initio Hartree-Fock (HF) or density functional theory (DFT) levels. Dispersive and repulsive contributions were evaluated by either Lennard-Jones or Buckingham equations using atomic (ionic) parameters for dispersive interactions originating from the London or Slater-Kirkwood theory and those for repulsive interactions resulting from the criterion of minimization of energy on separation of atoms (ions) equal to the sum of their van der Waals radii. Coulombic energies arising from charges fitted to MEP seem to be the most reliable. These values show a decreasing tendency with an increase of dimensions of ions (volume of basic stoichiometric units).