In this work, ab initio calculations were performed in order to study the vibrational spectra of the Bi2Sr2CaCu2O8 (Bi2212) compound. A structural modulation correction on some atomic positions, producing a distorted structure with lower symmetry, is used for the calculation. We argue that this correction allows to account for an average effect of the incommensurate superstructure, generating a more accurate representation of the real unit cell observed in this compound. A complete and conclusive vibrational assignment is performed, discussing the correspondences with previous experimental and theoretical reports. A brief analysis of the electronic density of states and band structure comparing the tetragonal and distorted unit cell is also included.

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In this work, the effect of strain on the vibrational and electronic properties of the YBa2Cu3O7(YBCO) compound was studied through \textit{ab initio} calculations. For this, two structural models were used: a bulk model and a surface model (a monolayer with CuO2 and BaO as the terminating layers). The phonon spectra was calculated for both structures under different levels of c axis strain. The most appreciable change occurs in the vibrational properties, and in the surface case. From the simulation of the Raman spectra, we were able to quantify the Raman shift ratio as a function of the applied strain, and analyzed its behavior in terms of the overlap population of the different bonds and the reduced mass of selected phonons. The effect of the level of deformation on the band structure and the electronic density of states is small for both structures, although more noticeable in the case of the surface model. In both cases, tendencies are observed when the fine features of the band structure are analyzed by means of the tight binding model. Due to the lower symmetry, the surface model also shows modifications of the bands related to the CuO2 planes.