
Accurate potential energy function and spectroscopic study of the X^{2}Σ^{+}, A^{2}П and B^{2}Σ^{+} states of the CP radical
Liu YuFang, Jia Yi
Chin. Phys. B, 2011, 20 (3):
033106.
DOI: 10.1088/16741056/20/3/033106
This paper calculates the equilibrium internuclear separations, the harmonic frequencies and the potential energy curves of the X^{2}Σ^{+}, A^{2}П and B^{2}Σ^{+} states of the CP radical by the highly accurate valence internally contracted multireference configuration interaction method with correlationconsistent basis sets (augccpV6Z for C atom and augccpVQZ for P atom). The potential energy curves are all fitted with the analytic potential energy function by the leastsquare fitting. Employing the analytic potential energy function, we determine the spectroscopic constants (B_{e}, α_{e} and ω_{e}χ_{e}) of these states. For the X^{2}Σ^{+} state, the obtained values of D_{e}, B_{e}, α_{e}, ω_{e}χ_{e}, R_{e} and ω_{e} are 5.4831 eV, 0.792119 cm^{1}, 0.005521 cm^{1}, 6.89653 cm^{1}, 0.15683 nm, 12535.11 cm^{1}, respectively. For the A^{2}П state, the present values of D_{e}, B_{e}, α_{e}, ω_{e}χ_{e}, R_{e} and ω_{e} are 4.586 eV, 0.703333 cm^{1}, 0.005458 cm^{1}, 6.03398 cm^{1}, 0.16613 nm, 1057.89 cm^{1}, respectively. For the B^{2}Σ^{+} state, the present values of D_{e}, B_{e}, α_{e}, ω_{e}χ_{e}, R_{e} and ω_{e} are 3.506 eV, 0.677561 cm^{1}, 0.00603298 cm^{1}, 5.68809 cm^{1}, 0.1696 nm, 822.554 cm^{1}, respectively. For these states, the vibrational states with the rotational quantum number J equals zero (J = 0) are studied by solving the radial nuclear Schr"odinger equation using the Numerov method. For each vibrational state, the vibrational level, the classical turning points, the rotational inertial and the centrifugal distortion constants are calculated. Comparison is made with recent theoretical and experimental results.
