Could a fractional spin number be possible
Posted: Wed Apr 10, 2019 12:43 am
Dear all and especially Prof. Graeme,
I was trying to calculate the spin charge density of the monomer of a homogeneous catalyst, the ball-and stick structure of which is as in the attachment. The atom in dark yellow and in the center is iron (Fe), linking to two ligands.
After a single-point energy calculation and issuing three commands:
chgsum.pl AECCAR0 AECCAR2
chgsplit.pl CHGCAR
bader CHGCAR_mag -ref CHGCAR_sum
I have got the spin numbers of all atoms of the system.
Oddly, the spin number for Fe atom is calculated to be 3.4991. Does it mean that the Fe atom has 3.5 unpaired electrons? Is it meaningful physically? Or is there anything wrong with my INCAR settings?
I was trying to calculate the spin charge density of the monomer of a homogeneous catalyst, the ball-and stick structure of which is as in the attachment. The atom in dark yellow and in the center is iron (Fe), linking to two ligands.
After a single-point energy calculation and issuing three commands:
chgsum.pl AECCAR0 AECCAR2
chgsplit.pl CHGCAR
bader CHGCAR_mag -ref CHGCAR_sum
I have got the spin numbers of all atoms of the system.
Oddly, the spin number for Fe atom is calculated to be 3.4991. Does it mean that the Fe atom has 3.5 unpaired electrons? Is it meaningful physically? Or is there anything wrong with my INCAR settings?