On the behavior of the low-lying 2Σ+ electronic states of NO

The electric-field gradients at both nuclei and the electric-dipole moments for low-lying 2Σ+ states of NO are calculated using the internally contracted multireference configuration interaction method. The changes in character of the wavefunctions with internuclear separation R are used to interpret the intricate pattern of the R-dependences of the physical quantities. The estimated magnitudes of the 14N nuclear quadrupole coupling constant and the electric-dipole moment at the N=0 and v=3 rovibrational level of the A 2Σ+ electronic state, 6.615 MHz and 0.950 D, respectively, are in good agreement with experimental data.