O 2 ENERGY LEVELS, BAND CONSTANTS, POTENTIALS, FRANCK- CONDON FACTORS AND LINELISTS INVOLVING THE X 3 g, a 1 g AND b 1 + g STATES SHANSHAN YU, BRIAN DROUIN, CHARLES MILLER, IOULI GORDON Jet Propulsion Laboratory, California Institute of Technology Harvard-Smithsonian Center for Astrophysics 6/17/20141TI14 Image courtesy of:
What is needed for comprehensive linelist? Energy level(s) Line position Degeneracy Intensity o Spin moments o Electronic correlations o Eigenfunction overlaps o Partition sums Lineshapes 6/17/2014TI142 Energy level(s) Line position Degeneracy Intensity – Spin moments – Electronic correlations – Eigenfunction overlaps – Partition sums Lineshapes Source:web.sahra.arizona.edu
2012 TA04 Simultaneously fit MW, THz, infrared, visible and UV transitions of 16 O 16 O, 16 O 17 O, 16 O 18 O, 17 O 17 O, 17 O 18 O, 18 O 18 O Treat all six O 2 isotopologues as the same molecule using well- known reduced mass relationships Leverage experimental information from one isotopologue to accurately predict the spectra of any other isotopologue Derive potentials from obtained parameters 6/17/2014TI143
Isotope Invariant Parameter Set (1) 6/17/2014TI144 (V max =31) (V max =10) (V max =12) TeTe ( 52) (149) 9100( 66)25556(149) GvGv (166) (173) ( 68) 2009(165)1905(171)1590( 60) ( 67) (229) ( 75) ( 99)63.28(217)25.09( 81) ( 56)-3.436( 61) (226) 6.31(134)E (114)E-03
6/17/2014TI145 (V max =31) (V max =10) (V max =12) BvBv (110) (198) (256) ( 91) (165) (213) (158) (282) ( 36) ( 39) ( 70) (105) (271) ( 56) ( 73)E ( 62)E-06 DvDv ( 43) (167) ( 59) ( 48)E (166)E ( 49)E (112)E (226)E-06 HvHv -1.34E-09 a E-06 a E-06 a 4.52( 73)E-09 Isotope Invariant Parameter Set (2)
6/17/2014TI146 (V max =31) ( 40) ( 55) (109) 8.31( 60)E ( 89) ( 52) 23.89( 46) (283)E ( 79) (210)E (124) ( 39) ( 54) (142)E ( 62)E ( 39)E-09 Isotope Invariant Parameter Set (3)
Method for deriving band parameters Math is straightforward But tedious for 6 isotopes, with 70 vibronic states each Especially if error propagation is desired! 6/17/2014TI147
Method for generating potentials 6/17/2014TI148 R.J. Le Roy, RKR1 2.0, A computer program implementing the first-order RKR method for determining diatomic molecule potential energy function, University of Waterloo, Chemical Physics Research Report CP-657R(2004); see Band Parameters 6 isotopes, 3 electronic states RKR turning points 6 isotopes, 3 electronic states Vibrational wavefunctions, Franck-Condon Factors 6 isotopes, 3 electronic states, 3 transitions
6/17/2014TI149
What is needed for comprehensive linelist? Energy level(s) Line position Degeneracy Intensity o Spin moments o Electronic correlations o Eigenfunction overlaps o Partition sums Lineshapes 6/17/2014 TI1410
Partition Sums Only need Degeneracy d i & Energy E i Then calculate as a function of temperature Total Internal Partition Sums from HITRAN Our calculations disagreed by error in Boltzmann constant for 16 O 2 and by d 0 for asymmetric isotopologues 6/17/2014TI1411
Partition Sums 6/17/2014TI1412
What is needed for comprehensive linelist? Energy level(s) Line position Degeneracy (quantum assignment) Intensity o Spin moments o Electronic correlations o Eigenfunction overlaps o Partition sums Lineshapes 6/17/2014TI1413
Theory for transition moments in O 2 6/17/2014TI1414 O = O 33 11 11 N = 2 S = 1, L = 2 N = 0,+1,+2 S = 0 L = 2 N = 0,+2 = spin D rot S = 1, L = 0 N = 0,+1,+2,+3 N = 1 = Q elec D rot
Transition Moments 6/17/2014TI1415
Transition Intensities 6/17/2014TI1416 Flat lines indicate scaling factor Siedways ‘w’s indicate Herman-Wallis factor
Conclusion Predictions from literature, SPCAT, RKR1 SPCAT predictions for all O2 states below cm- 1 are almost as good as HITRAN12 Details of J dependence of intensity still an issue for ‘A-band’ Lineshape is not part of SPCAT, need to apply alternate method Method produces ‘good’ extrapolative listings of isotopes, hot bands, difference bands 6/17/2014TI1417
Acknowledgements NASA ACLR OCO-2 ABSCO Herb Pickett 6/17/2014TI1418 © 2014 California Institute of Technology. Government sponsorship acknowledged.