On the ground state of TiO2 as predicted by all electron density functional calculations in relation to experiment
Department of Physics and Astronomy, University of Missouri,
a e-mail: email@example.com
Received in final form: 31 August 2017
Published online: 7 November 2017
The energy ordering of rutile and anatase forms of TiO2 are reported with several density functionals as obtained using all electron calculations. Careful convergence tests were performed. Results obtained both with and without structure optimization are reported. In each case anatase is found to be more stable than rutile, in contrast to the experimental expectation. Upon full relaxation, the lattice parameters of both forms are similar to experiment regardless of the functional used. GGA functionals, which are generally regarded to be more reliable than the LDA for energies, yield a more strongly stable anatase ground state. The possibility of a poor approximation to the Ti core-electrons in pseudopotential methods can be excluded as a source of this long standing puzzle. The results are discussed in relation to experiment.
Key words: Solid State and Materials
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2017