Potential energy, dipole moment, and electronic transition moment functions for the A 3 Π and X 3 Σ - states of PH have been calculated from highly correlated electronic wavefunctions. The electric dipole moments in the vibrational ground state of PH are calculated to be 0.637 Debye (A 3 Π ) and 0.403 Debye (X 3 Σ - ). The predicted rates of spontaneous emission between low lying vibrational states of the X state lie in the range of 46 to 109 sec -1 (PH) and 12 to 30 sec -1 (PD). The calculated radiative lifetime of the v' = 0 level in the A 3 Π state of 400 ns is lower by about 10 percent than the most recent experimental value. The classical intersection of the 5 Σ - and the A 3 Π state has been calculated to lie between v' = 2 and 3 with an expected uncertainty of about 500 cm −1 , whereas the onset of the rotationally dependent predissociation lies at v' = 0, J' = 11.