negative d-band center

[mmg016]

Dear all,

I am calculating the d-band center using the ''dosanalyze.pl' script.
For instance, I know that the surface atoms 2, 3, 8 are involved in the bonding of my adsorbate. Thus, I am interested in calculating the d-band center for these thee atoms.

Therefore,
dosanalyze.pl 2 3 8
No energy range specified, integration will cover the whole range.
When no band is selected, will analyze d band

Total States: 522.33112951
Average Energy (band center): -1.34832093505096
Standard Deviation: 1.88582610701162

I am getting a negative d-band center of -1.348. What does a negative d-band-center signify physically?

Thank you for your insights.

Best regards,
mmg016

[graeme]

This means that the d-band center is below the Fermi level.