Hybrid exchange–correlation functionals for van der Waals TiSe2 material: Parametrization versus a posteriori D3 dispersion corrections

• D3 Grimme’s dispersion showed low correction for all evaluated properties. • HSE06 functional presented more deviation because of Hartree-Fock exchange term. • Low vibrations were poorly described. • PBE0 functional described better the properties. Superconductivity is one of the most interesting electrical phenomena found in Physical Science. The null electrical resistance provides a unique free displacement for the electrons into the material. TiSe 2 is a superconductor material below 4K, creating a charge density wave as electrical propagation. Gaussian basis sets or exchange–correlation functionals poorly described the high interaction distance as van der Waals force because of low exchange–correlation energy. One physical–mathematical tool to indicate long-range distance is the Grimme's or D3 dispersion. In this work, quantum simulations based on DFT using periodic models depicted in CRYSTAL17 code investigated the TiSe 2 material regarding PBE0, HSE06, and B3LYP functionals and Grimme's dispersion. In particular, the high covalent feature on the Ti–Se chemical bond is challenging for DFT functionals, while van der Waals interaction between lamellas is essential for crystalline structure. Then, relative errors quantified the functional descriptions to evaluate the influence of hybrid and parameterized hybrid functionals on this critical material's structural, electronic, and vibrational properties.