Partial Density of states –
In order to investigate the electronic properties, variation in the
HOMO-LUMO gap and chemical bonding nature due to TM metal doping in
Ge12 cage cluster, we have performed subtleties
examination of the atomic orbital to examine the contribution of
different TM’s (s, p, or d) and Ge (s, p) orbital’s by calculating
partial density of states (PDOS). The DOS is acquired by utilizing
GaussSum programming [41]. It very well may be
seen that the partial density of states means the number of different
states where the electrons are allowed to occupy at a particular energy
level can be significantly change when the Ge12 cluster
are doped with Tc, Pd, Zr, and Co atoms. As shown in the figure 6, the
density of states of pure Ge12 cluster, the position of
spin up and spin down DOS are same but after the doping of TM’s (Tc, Pd,
Zr, and Co) the spin up and spin down states in DOS exhibit the presence
of electronic polarization.
The PDOS provide basic analysis of the interaction between the TM’s atom
orbital’s and germanium cage. The peak of spin up and spin down near the
Fermi level define the localization domains and corresponds to
chemically reactive regions. The charge transfer between the TM atoms
and the germanium cage generate the electric field, on the basis of this
charge transfer, polarization can be explained. Study of natural bond
orbital analysis [Supplementary Information] explain that electronic
states near the Fermi level mainly come from 4s, 4p orbital’s of
germanium cage and 4d orbital of TM atoms. As we can see in table 2
[SI] that there are 4s1.604p2.38 orbital contributions of Ge atom and
4d9.55 orbital contribution of Pd atom are mainly
dominated near the Fermi level of Ge12Pd system. These
all contribution has shown in alpha dos in the PDOS figure 6 and the p-d
hybridization is mostly responsible for localized electrons near the
Fermi level. Similarly, In Ge12Tc, there is
4s1.55, 4p2.30 orbital of Ge atom
4d7.63 orbital of Tc atom are contributing near the
Fermi level and it is also clear from the PDOS.