The VUV absorption spectrum of PN obtained by the pyrolysis of P3N5 ha
s been observed using the synchrotron radiation of SUPERACO in Orsay,
France. Numerous new Rydberg states have been observed between 600 and
1000 Angstrom. They have been classified in Rydberg series converging
to ionization energies of 15.712 +/- 0.011 eV and 16.675 +/- 0.011 eV
(in perfect agreement with previous photoelectron values). An ionizat
ion limit of 18.8340 +/- 0.0063 eV corresponding to the D-2 Sigma(+) s
tate of PN+ has been experimentally determined for the first time. (C)
1995 Academic Press, Inc.