236750.fig.005a
(a)
236750.fig.005b
(b)
236750.fig.005c
(c)
236750.fig.005d
(d)
236750.fig.005e
(e)
236750.fig.005f
(f)
Figure 5: The stretching potential curves of the five singlet states ( , , , , and state) of CH2 as functions of the bond length with the ∠HCH fixed at (a) 180°, (b) 175°, and (c) 160°, respectively; The Renner-Teller terms , , , and ( ) as functions of the bond length with ∠HCH fixed at (d) 180°, (e) 175°, and (f) 160°, respectively. is fixed at 2.09 bohrs, and the zero energy is taken at the CH2 ( ) minimum.