Units

DOS curves come out in (eV)^(-1). Non-spin cases have an extra factor
of 2. For spin-polarized systems, two curves are output.

COOP curves come out in (eV)^(-1) and *per spin*.  If they are
integrated up to the Fermi level, (including all the interactions for
all orbitals, even those on-site (for this, specify a minimum distance
of 0.0 in the .mpr file and a big enough maximum distance)), the
result is N/2 (half the number of electrons in the unit cell) when the
system is not spin-polarized. When there are two spin components, two
curves are ouput in the .coop file, and the sum of the integrals for
both would be N.

COHP curves come out in Ry * (eV)^(-1) and *per spin* (the Ry part
comes from the Hamiltonian factor).  If they are integrated up to the
Fermi level, (including all the interactions for all orbitals, even
those on-site (for this, specify a minimum distance of 0.0 in the .mpr
file and a big enough maximum distance)), the result is E_bs/2 (half
the band-structure energy) when the system is not spin-polarized. When
there are two spin components, two curves are ouput in the .cohp file,
and the sum of the integrals for both would be E_bs.

It is important to note that E_bs is *not* the Kohn-Sham energy, 
but the sum of KS eigenvalues up to the Fermi level (with the
appropriate k-point weights). E_bs is now computed by Siesta
as Tr(DM*H), where DM is the density matrix (see the Siesta paper)
and output as Ebs.

E_bs can also be computed integrating the DOS curves:

E_bs = Integral (DOS(E)*E*dE)

up to the Fermi level. NOTE that the DOS curves for the non-spin case
*already* have the factor of 2.  Mprop now includes a third column in
the Filename.intdos file showing the integrated E_bs(E). By reading
the entry for a value of E close to the Fermi level E_bs can
estimated. This is useful to get Ebs for legacy calculations performed
with versions of Siesta that did not compute E_bs.

In order for mprop to estimate the Fermi level accurately (to match
Siesta's own value), it is advisable to use a small smearing. By using
a relatively high number of sampling points ( -n option), and an
energy upper limit that matches E_fermi, the COOP and COHP curves can be
easily integrated by a simple sum (and a factor of the spacing).

For example:

mprop -s 0.1 -n 1000  -M E_fermi  Filename ( no .mpr extension)

