First-principles calculations of structural, electronic, and optical absorption properties of CaCO3 Vaterite

摘要: Abstract First-principles calculations are performed within the density functional theory (DFT) for CaCO 3 vaterite polymorph considering exchange-correlation potentials in local approximation (LDA) and generalized gradient (GGA). The crystal structure of is considered to be orthorhombic, although there considerable debate literature about a possible hexagonal cell with disordered carbon oxygen atoms. After convergence, calculated orthorhombic lattice parameters demonstrated good agreement experimental results. direct energy gap preview wide estimated LDA GGA E G ( Γ → ) = 4.68 eV 5.07 , but should underestimate actual value yet measured. optical absorption intensity previewed relevant energies larger than 6.2 eV.