primary (photo)process [obsolete] 

https://doi.org/10.1351/goldbook.P04839
The term primary (photo)process for photophysical processes is apt to lead to inconsistencies, and its use is therefore discouraged.
Source:
PAC, 1996, 68, 2223. (Glossary of terms used in photochemistry (IUPAC Recommendations 1996)) on page 2266 [Terms] [Paper]