Multiwfn forum

I have a metal carbonyl complex (Ligand)Fe(2+)(CO)2. I followed the tutorial in the manuscript for the CDA of (Cl)2Pt(NH3)2, so I calculated the fragments L, (CO)2 and Fe2+.

The result of the CDA (option 16) for d is: Fe2+ -> (CO)2 0.057 e and for b: (CO)2 -> Fe2+ -0.529 e, if the order is Fe(CO)2L (Fe2+ is the first and L the last fragment: fragments 1,2). When I change the order to (CO)2LFe I get: d: (CO)2 ->  Fe2+ -0.529 and b:  Fe2+ -> (CO)2 0.057 (fragments 1,3), which is the same result.

My problem is, that I don't understand the negative (-) sign. I would understand if 0.529 electrons are donated from CO to Fe2+ and 0.057 e are back donated from Fe2+ to CO. Can anyone help? Thank you in advance.