CH2 revisited

The first four states of the CH2 molecule ((X) over tilde B-3(1), (a) over tilde (1) A(1,) (b) over tilde (1)A(1), and (c) over tilde (1)A(1)) are examined using state-of-the-art ab initio methods and basis sets. The construction of potential energy curves with respect to the C + H-2 and CH + H channels provides significant clues to understanding the geometric and electronic structure of the above states. All of our numerical findings are in excellent agreement with the existing experimental data.