We investigate the low-temperature charge-density-wave (CDW) state of bulk TaS2 with a fully self-consistent DFT+U approach, over which the controversy has remained unresolved regarding the out-of-plane metallic band. By examining the innate structure of the Hubbard U potential, we reveal that the conventional use of atomic-orbital basis could seriously misevaluate the electron correlation in the CDW state. By adopting a generalized basis, covering the whole David star, we successfully reproduce the Mott insulating nature with the layer-by-layer antiferromagnetic order. Similar consideration should be applied for description of the electron correlation in molecular solid.
@article{arxiv.2104.00346,
title = {Identification of the Mott insulating CDW state in 1T-TaS$_2$},
author = {Dongbin Shin and Nicolas Tancogne-Dejean and Jin Zhang and Mahmut Sait Okyay and Angel Rubio and Noejung Park},
journal= {arXiv preprint arXiv:2104.00346},
year = {2021}
}