Article History

Received: 9 January 2017

Accepted: 26 July 2017

First Online: 26 September 2017

Change Date: 11 May 2018

Change Type: Correction

Change Details: The original version of this Article contained errors in Fig. 2, Fig. 3a–c and Supplementary Fig. 2. In Fig. 2g and Supplementary Fig. 2, the band structure plot calculated from density function theory (DFT) had a missing band of mainly <i>z</i>² character that starts at about – 0.25 eV at the <i>Y</i> point and disperses downwards towards the Γ point. This band was inadvertently neglected when transferring the lines from the original band plot to the enhanced version for publication. Also in Fig. 2g, the points labelled <i>M</i> and <i>Y</i> were not exactly at (1/2 1/2 0) and (0 1/2 0), but rather (0.52 0.48 0) and (0 0.48 0) due to a bug in XCrysDen for low-symmetry structures that the authors failed to identify before publication. Thus, the bands presented were slightly off the true <i>M</i>–<i>Y</i> direction and additional splitting incorrectly appeared (in particular for the highly dispersive bands of <i>x</i>²–<i>y</i>² character). The correct versions of Fig. 2g (cited as Fig. 1) and Supplementary Fig. 2 (cited as Fig. 2) are:

Change Details: which replaces the previous incorrect version, cited here as Fig. 3 and Fig. 4:

Change Details: Neither of these errors in Fig. 2g or Supplementary Fig. 2 affects either the discussion or any of the interpretations of the ARPES data provided in the paper. The authors discussed the multilayer band splitting along the Γ–<i>M</i> direction (<i>δ</i> band and <i>α</i> band as assigned in the paper), and ARPES did not see any split band. The authors did not discuss the further splitting that arises due to back folding along the <i>M</i>–<i>Y</i> direction.

Change Details: In Fig. 3a–c, the errors in the <i>M</i> and <i>Y</i> points in Fig. 2g cause subtle changes to the DFT dispersions. The correct version of Fig. 3a–c is cited here as Fig 5:

Change Details: which replaces the previous incorrect version (Fig. 6):

Change Details: However, the influence on the effective mass results of Fig. 3d is negligible.

Change Details: These errors have now been corrected in both the PDF and HTML versions of the Article. The authors acknowledge James Rondinelli and Danilo Puggioni from Northwestern University for calling our attention to these issues.

Competing interests

: The authors declare no competing financial interests.