Theoretical spectroscopic characterization of the `B POT. 2´`sigma POT. +´ state of SiP and of the `X POT. 2´II-`B POT. 2´`sigma POT. +´ and `A POT. 2´`sigma POT. +´-`B POT. 2´`sigma POT. +´ transitions - Ornellas, Fernando Rei (Chemical Physics Letters, 2001)