Extensive ab initio study of the electronic states of CP radical including spin-orbit coupling

► Effect on the PECs by core-valence correlation and relativistic corrections is included. ► Effect on the energy splitting by core-electron correlations is discussed. ► Spectroscopic parameters of 17 Λ-S bound states are calculated. ► Spectroscopic parameters of 13 Ω states are investigated. ► Present spectroscopic parameters achieve high quality.