Year | Experimental Method | Theoretical Model | Estimated Band Gap [eV] | Reference |
1963 | T dependent resistivity | - | 0.4 | [33] |
1979 | - | LSDA | 0.3 | [44] |
2001 | - | GW | 0.8 ± 0.1 | [45] |
2002 | ARPES & RIXS | - | >1.0 | [35] |
2002 | - | GW | 0.0 | [37] |
2003 | ARPES | - | 1.0 | [36] |
2004 | EELS | LDA** | 0 | [38] |
2004 | e-transport, tunneling | - | 0.2 and 1.0 | [43] |
2005 | - | sX-LDA | >1.2 | [46] |
2008 | - | QMC | 1.3 | [39] |
2008 | - | LSDA | 0.2 | [40] |
2009 | - | GGA-HCTH | 0.85 | [47] |