CCL: electron affinity

[Mikael Johansson <mikael.johansson[-]helsinki.fi>]

 Sent to CCL by: Mikael Johansson [mikael.johansson]_[helsinki.fi]
 Hello Ramasami and All!
 On Wed, 8 Nov 2006, Dr. Ponnadurai Ramasami ramchemi!A!intnet.mu wrote:
>  I am calculating the electron affinity of carbon monoxide using =
>  B3LYP/aug-cc-pVTZ by evaluating E(CO, neutral) - E(CO, negative).
>  I am getting a negative value of -100.2 kJ/mol.
>  The literature experimental value is 127.9 kJ/mol (I guess positive).
>  Is this correct?
>  Can electron affinity be negative?
The sign should at least be correct; the CO anion is not stable. The
 following paper might be of interest:
A. Dreuw, L. S. Cederbaum, "Long-lived high-spin states of small
 anions:
 6PI state of CO-", Phys. Rev. A 59 (1999) 2702-2706.
 Have a nice day,
     Mikael J.
     http://www.iki.fi/~mpjohans/