A Precise Description of the Electronic Structures and Spin-Allowed Transition Properties of PF and Its Cation: All-Electron Configuration-Interaction Investigations Including Relativistic Effect*Supported by the National Natural Science Foundation of China under Grant No 11404180, the Natural Science Foundation of Heilongjiang Province under Grant Nos F201335, A2015010, and A2015011, and the Postdoctoral Scientific Research Developmental Fund of Heilongjiang Province under Grant No LBH-Q14159. (July 2015)