1. Ab initio calculations of highly excited NH3 levels
Oleg Polyansky
Physics and Astronomy
University College London
Urbana
June 2016
Image credit Shutterstock

2. Completeness: Absorption of ammonia (T=300 K)
BYTe
Less than 30,000 NH3 lines are known experimentally: our list contains 1.1 billion lines, or about 40,000 times as many! They represent all the allowed transitions between 1.2 million upper and lower ro-vibrational states, whose individual quantum numbers are detailed in the list. For comparison, it is worth noting that our earlier T=300 K NH3 line list comprises only 3.25 million transitions between 184,400 states. It has an upper energy cut-off of 12,000 cm-1 and a maximum rotational quantum number J=20.
Less than 30,000 NH3 lines known experimentally:
BYTe contains 1.1 billion lines, about 40,000 times as many!
S.N. Yurchenko, R.J. Barber & J. Tennyson, Mon. Not. R. astr. Soc., 413, 1828 (2011) 2

3. Frontier Problems in Exoplanet Characterization
Non-equilibrium processes in exoplanet atmospheres
(Stevenson et al. 2010; Madhusudhan & Seager 2011; Moses et al. 2013) CH4, CO, NH3
Constraints on thermal inversions in hot Jupiters
(Fortney et al. 2008; Spiegel et al. 2009) TiO, VO, H2S
C/O ratios and Carbon-rich atmospheres
(Fortney et al. 2008; Spiegel et al. 2009) H2O, CO, HCN, CH4,
C2H2,TiH, FeH
Constraints on exoplanet formation conditions
(Madhusudhan et al. 2011; Oberg et al. 2011) H2O, CO, CH4
Atmospheres and interiors of super-Earths
(Bean et al. 2011; Desert et al. 2011; Miller-Ricci Kempton et al ) H2O, CO2
Frontier Problems in Exoplanet Characterization
Polish this slide. Order the points properly, etc..
Slide courtesy of N Madhusudhan (Cambridge)

4. Results Hot Jupiter, eclipse
Retrieve majority of temperature profile, H2O, CO2 and CH4 well.
Not so good at CO and NH3 – not so many absorption lines and those present are contaminated by H2O/CO2.
Only upper limit on CO and NH3 achievable where VMR falls below 100 ppmv.
Barstow et al. 2013a

5. Transmission of main candidate molecules
(H2O, CO2, CO, CH4,NH3)

6. Completeness: Absorption of ammonia (T=300 K)
BYTe
Less than 30,000 NH3 lines are known experimentally: our list contains 1.1 billion lines, or about 40,000 times as many! They represent all the allowed transitions between 1.2 million upper and lower ro-vibrational states, whose individual quantum numbers are detailed in the list. For comparison, it is worth noting that our earlier T=300 K NH3 line list comprises only 3.25 million transitions between 184,400 states. It has an upper energy cut-off of 12,000 cm-1 and a maximum rotational quantum number J=20.
Less than 30,000 NH3 lines known experimentally:
BYTe contains 1.1 billion lines, about 40,000 times as many!
S.N. Yurchenko, R.J. Barber & J. Tennyson, Mon. Not. R. astr. Soc., 413, 1828 (2011) 6

7. H2OF+H2O H2F+ NH3 H3O+ CH4 H2O H2F+ NH3 H3O+ CH4
Молекулы с числом электронов :
H2OF+H2O
H2F+
NH3
H3O+
CH4
H2O
H2F+
NH3
H3O+
CH4
Вариационные программы:
TROVE (3,4 атома)
DVR3D (3 атом)

8. Figure 1. Schematic energy level diagram employed in experiment.
Our prediction
cm-1
Global ab initio PES so far
~10 cm-1

9. H2O pokazatel
0.01
0.06
-0.02
-0.05
0.04
-0.04
0.00
-0.07
0.02
-0.08
0.05
-0.06
-0.23
-0.01
0.15
0.03
0.83
0.42
0.43
-0.03
0.16
-0.16
-1.72
12565
-8.18
0.67
-0.56
-2.05
0.19
-2.31
0.41
0.56
-5.56
0.22
-2.84
0.54
1.11
0.52
1.22
-0.59
0.25
-4.14
-0.72
1.10
1.99
0.24
3.88
0.11
1.26
-0.92
2.09
-8.59

10. BT2 (water) – 0.5 Billion lines
H216O POKAZATEL
BT2 (water) – 0.5 Billion lines
POKAZATEL – 10 billion lines, first complete
Linelist of polyatomic molecule, every transition
Between every bouind state is included
POKAZATEL – PolyanskyOleg,Kyuberis Aleksandra, Zobov nikolAi, Tennyson, Lodi,(and Yurchenko)

11. H216O, J=0-72, T=296K, Pokazatel, 13000-25000cm-1
H216O, J=0-50, T=296K, BT2, cm-1

12. Structure of the talk Why we did what we did What we did for NH3
How we have done it

13. Low lying energy levels of NH3

17. Recently assigned NH3 band origins
Band obs BYTe ab initio
(v1 + v2 + 2v42)
(v1 + v2 + 2v42)
(v1 + v2 + v31)
(v2 + 2v32)
(v2 + 2v32)
(2v1 + v41)
(v1 + v31 + v41)
(v1 + v31 + v41)
(v1 + 3v41)
(v1 + 3v41)
(v1 + 2v2 + 2v42)
(2v32 + v41)
(2v32 + v41)
E. Burton et al., JMS, v.325, p.7 (2016)

18. Highly excited experimental energy levels - calculations
v1 v2 v3 v4L3L4
Obs (cm-1)
Calc (cm-1)
Obs-Calc (cm-1)
6520
0.79
6606
-0.14
-2.56
-2.89
0.64
-0.89
-8.16
-6.92
-15.18
-9.95
Lehmann, K et al. exp. NH3

20. Prediction and reality for vOH=10
(10,0+, 0)

21. K. Lehmann et al.- exp.

22. Figure 2 Spectrum of transitions to the states below D0
Figure 2 Spectrum of transitions to the states below D0. Transitions from the gateway state prepared via the pathway: [ cm1, 110 (80)+0]  [ cm1, 111 (40)-0]  [ cm1, 212 (00) 0]. The combination of laser polarisation used and selection rules results in final states with J = 1 or 2. State labels are as in Fig. 1

24. Structure of the talk Why we did what we did What we did
How we have done it

25. 12 FACTORS 1. MRCI , MOLPRO ~Full CI
Born-Oppenheimer
1. MRCI , MOLPRO ~Full CI
2. Number of points cm-1
3. All electrons, CV cm-1
4. Highest basis set aug-cc-pCV6z cm-1
5. CBS cm-1
6. Optimized (higher) CAS cm-1
Corrections
7. Adiabatic (DBOC) cm-1
8.Relativistic (MVD1, Gaunt (Breit), ) cm-1
9. QED cm-1
10. SO – 40 cm-1
11. Vibration non-adiabatic
(D. Schwenke, P. Bunker) cm-1
12. Rotational non-adiabatic (S.Sauer) cm-1

26. TROVE Yurchenko S. N. , Thiel W., Jensen P.
Theoretical ROVibrational Energies (TROVE): A robust numerical approach to the calculation of rovibrational energies for polyatomic molecules
J MOL SPECTROSC , 245 (2) 126 – 140, (2007)

27. CONCLUSIONS
Ab initio NH3 PES and DMS has been calculated Energy levels from 6000 cm-1 to 8000 cm-1 calculated more accurately than fitted PES Energy levels between cm-1 nd cm-1 have been calculated ab initio Starting point for a global PES and Linelist