We present the relation between Nuclear Magnetic Resonance (NMR) of ۳۱P, optoelectronic and thermoelectric properties of MP۳ (M = Ir, Co, Rh, Ni) compounds. Full potential linearized augmented plane wave (FP-LAPW) method and PBE-GGA/ mBJ plus spin–orbit coupling (SOC) approach are used for prediction of all spectra. Obtained ۳۱P isotropic magnetic shielding value decreases from ۶۰.۵ ppm for IrP۳ to −۱۳.۳۵ ppm for NiP۳ due to the decreasing band gap as IrP۳ > CoP۳ > RhP۳ > NiP۳. The results demonstrate linear relationships between the magnetic shielding and chemical shifts. It is found that Plasmon energy decreases from about ۲۴.۴۳ for IrP۳ to ۲۱.۹۷ eV for NiP۳. Obtained results show that isotropic magnetic shielding for ۳۱P has a dominating effect on the optoelectronic and thermoelectric properties of these compounds.