The electronic structure and plastic properties are investigated for a number of alkali halide crystals (CsCl, CsBr, CsI). First-principles calculations are carried out within the Hartree-Fock and density-functional theory approximations using several variants of the exchange-correlation functional, including the hybrid exchange technique. The results obtained with the use of five methods are compared with the available experimental data. The tendencies revealed in the variations in the band parameters and plastic properties of the crystals under investigation are analyzed.