on Mass Spectrometry and Allied Topics, Altanta, Ga., May. 1971. 221. Koyano, I. Omura, and I. ... 23 R. C. Dunbar, J. Am. Chern. Soc. 90, 5676 (1968); 93, 4167.
Variational Wavefunctions for H2+ Frank Weinhold and Allan B. Chinen Citation: J. Chem. Phys. 56, 3798 (1972); doi: 10.1063/1.1677782 View online: http://dx.doi.org/10.1063/1.1677782 View Table of Contents: http://jcp.aip.org/resource/1/JCPSA6/v56/i8 Published by the American Institute of Physics.
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DUNBAR,
SHEN,
9 M. T. Bowers, D. D. Elleman, and J. L. Beauchamp, J. Phys. Chern. 72, 3599 (1968). 10 A. G. Marshall and S. E. Buttrill, Jr., J. Chern. Phys. 52, 2752 (1970). 11 G. C. Goode, A. J. Ferrer-Correia, and K. R. Jennings, Intern. J. Mass Spectrometry Ion Phys. 5, 229 (1970). 12 F. H. Field and D. P. Beggs, J. Am. Chern. Soc. 93, 1585 (1971). 13 J. H. Futrell, F. P. Abramson, A. K. Bhattacharya, and T. O. Tiernan, J. Chern. Phys. 52, 3655 (1970). 14 Our observation of C.Hn+ is entirely reasonable in light of previous work. The extent of production of a collision-stabilized product ion is readily seen to be directly proportional to the time T that ions spend in the reaction region and proportional to the square of the pressure P. In Ref. 5, the production of C.Hu+ was of the order of 1% of the total ion current at a pressure of 10-2 tOfr and a time T of about 1.5X 10-5 sec. We observed a production of C.Hn+ of about 0.3% of the total ion current at a pressure of roughly 3 X 10-' torr. This would indicate an ion residence time of about 5X 10-3 sec, by no means unreasonable for conditions of low drift fields in the ICR cell.
THE JOURNAL OF CHEMICAL PHYSICS
AND
OLAH
15 R. M. Haynes and P. Kebarle, J. Chern. Phys. 45, 3899 11966). 16 A. G. Harrison, "Correlations of Fragment Ion Structures with Energetics of Formation," in Topics In Organic Mass Spectrometry, edited by A. L. Burlingame (Wiley, New York, 1970). 17 J. Collin and F. P. Lossing, J. Am. Chern. Soc. 79, 5848 (1957). 18 J. Collin and F. P. Lossing, J. Am. Chern. Soc. 80, 1568 (1958) . 19 G. B. Kistiakowsky and J. V. Michael, J. Chern. Phys. 40, 1448 (1964). 20 K. B. Wiberg, W. J. Bartley, and F. P. Lossing, J. Am. Chern. Soc. 84, 3980 (1962). 21 F. P. Lossing, reported at the Nineteenth Annual Conference on Mass Spectrometry and Allied Topics, Altanta, Ga., May 1971. 221. Koyano, I. Omura, and I. Tanaka, J. Chern. Phys. 44, 3850 (1966) . 23 R. C. Dunbar, J. Am. Chern. Soc. 90, 5676 (1968); 93, 4167 (1971 ).
VOLUME ,16, NUMBER 8
15 APRIL 19;2
Variational Wavefunctions for H 2 + FRANK WEINHOLD' AND ALLAN
B.
CHINEN
lJepartment of Chemistry, Stanford University, Stanford,
Ca1~fornia
94305
(Received 16 December 1971) The usual approximations to the molecular orbitals of H.+ are shown to have an improper exponential dependence on the radial elliptic coordinate A. However, the exact A dependence is easily incorporated into simple trial functions and leads to substantially improved numerical accuracy for both the Is
