Theoretical study on N/sub 2//sup +/, P/sub 2//sup +/, As/sub 2//sup +/, NP/sup +/, NAs/sup +/, and PAs/sup +/: Hyperfine coupling constants for 1/sup 2/ Sigma /sub (g)//sup +/, and electron-spin g-factors for 1/sup 2/ Sigma /sub g//sup +//1,2/sup 2/ Sigma /sub u//sup +/(X/sub 2//sup +/) and 1,2/sup 2/ Sigma /sup +/(XY/sup +/) states