Bonding, multiplicity and quantum chemistry for FeP2
Admittedly it is vacuum phase, but are you certain about your oxidation state assignments?  "nearly temperature independent susceptibility of -(8.8±0.7)centerdot10-6SI (at room temperature)"

doi:10.1016/j.jpcs.2013.04.015 
https://sciborg.uwaterloo.ca/~lfnazar/publications/Electrochem_Solid-State_Lett_6_8_A162-A165_2003.pdf  
doi:10.1021/ja301173q  
http://www.staff.uni-bayreuth.de/~bt220235/refs/HPR_29_235.pdf  
doi:10.1088/0031-8949/4/3/010 (given)