Analysis of interactions between excited Analysis of interactions between excited vibrational states in the vibrational states in the FASSSTFASSST

rotational spectrum of S(CN)rotational spectrum of S(CN)22

Zbigniew Kisiel, Orest Dorosh

Institute of Physics, Polish Academy of Sciences

Ivan R. Medvedev, Marcus Behnke, Manfred Winnewisser,Frank C. De Lucia, Eric Herbst,

Department of Physics, The Ohio State University

61st OSU International Symposium on Molecular Spectroscopy TH0961st OSU International Symposium on Molecular Spectroscopy TH09

The challenge:The challenge:The challenge:The challenge:

The solution:The solution:The solution:The solution:

FASSST mmw spectrum (see WI04)

continuous 110.1 – 374.3 GHz spectrum recorded at OSU at frequency accuracy of ca 50 kHz, resolution of 0.5-1 MHz, and containing >100000 measurable lines

Computer packages for efficient data reduction =

CAAARSCAAARS (WI04) and AABSAABS

http://info.ifpan.edu.pl/~kisiel/http://info.ifpan.edu.pl/~kisiel/prospe.htmprospe.htm

http://info.ifpan.edu.pl/~kisiel/http://info.ifpan.edu.pl/~kisiel/prospe.htmprospe.htm

Synchronized Synchronized cursors and cursors and

frequency axesfrequency axes

Name of data file for Name of data file for the fitting programthe fitting program

Quantum numbers of the Quantum numbers of the current transition (up to current transition (up to

six per energy level)six per energy level)

Predictions for many spectroscopic Predictions for many spectroscopic species can be displayed species can be displayed

simultaneously and differentiated with simultaneously and differentiated with various color, linestyle and highlighting various color, linestyle and highlighting

SVIEW_L = spectral viewerSVIEW_L = spectral viewer

ASCP_L = viewer of predictions

ASCP_L = viewer of predictions

Indicator of transition Indicator of transition already in the fitting already in the fitting

datasetdataset

Name of predictions Name of predictions file containing the file containing the current transitioncurrent transition

Indicator of synchronized operation Indicator of synchronized operation when a single keystroke actions when a single keystroke actions measurement of line closest to measurement of line closest to

prediction and adds the frequency and prediction and adds the frequency and quantum numbers to the datasetquantum numbers to the dataset

Synthetic overview of the ground state dataset Synthetic overview of the ground state dataset Synthetic overview of the ground state dataset Synthetic overview of the ground state dataset

Symbol size is proportional to: (obs-calc)/Red symbols denote (obs-calc) > 3

Lowest energy vibrational states in S(CN)Lowest energy vibrational states in S(CN)22 Lowest energy vibrational states in S(CN)Lowest energy vibrational states in S(CN)22

4= 122 cm-1 A1

7= 328

8= 366 9= 372

3= 496

Frequencies are unscaledB3LYP/6-31G(d,p)

Other modes (cm-1):

obs. calc.

2 672 685 A1

6 690 688 B1

5 2180 2293 B1

1 2308 2308 A1

B1

B2A2

A1

Loomis-Wood plot centered on Ka = 1 - 0 transitions in the ground stateLoomis-Wood plot centered on Ka = 1 - 0 transitions in the ground state

8 = 1 7 = 1

9 = 1

gs = 2 = 34 = 1

4 = 3

9 = 1, Ka=1- 0

Ka=2- 1 Ka=3- 2

Perturbations between Perturbations between 8 = 1 and and 9 = 1 visible in visible in RR-type transitions-type transitionsPerturbations between Perturbations between 8 = 1 and and 9 = 1 visible in visible in RR-type transitions-type transitions

Perturbations Perturbations (8 = 1 9 = 1) and and ( 8 = 1 4 = 3)Perturbations Perturbations (8 = 1 9 = 1) and and ( 8 = 1 4 = 3)

R-type Q-type

4 = 3

A1

8 = 1

B2

9 = 1

A2

A1 B2= B2

Ra: E + Fbc+… (4 constants)

A2 B2= B1

Rc: E + Fab+… (8 constants)

(c) = 0 !

A1 A2= A2

Rb: Fac+… (3 constants)

Hcor = i(G +…)P+ (F +…) (PP+PP)…

Plots of (1-pmix) for energy levels in the interactingtriad near 370 cm-1

Plots of (1-pmix) for energy levels in the interactingtriad near 370 cm-1

Plots of obs-calc differences for measured rotational transitions in the 370 cm-1 triad

Plots of obs-calc differences for measured rotational transitions in the 370 cm-1 triad

4 = 4

A1

8 = 1 4 = 1

B2

9 = 1 4 = 1

A2

A1 B2= B2

Ra: E + Fbc+…(4 constants)

A2 B2= B1

Rc: E + Fab+… (8 constants)

A1 A

2= A2

Rb : F

ac+…(3 constants)

3 = 1

A1

A1 A1= A1

W14 +… (3 constants)

A1 A2= A2

Rb: Fac+…(3 constants)

B 2 A 1

= B 2

R a:

E + F bc

+…

(4 co

nsta

nts)

(1-pmix) plots for the interacting tetrad of states near 500 cm-1(1-pmix) plots for the interacting tetrad of states near 500 cm-1

Obs-calc plots for the interacting tetrad of states near 500 cm-1Obs-calc plots for the interacting tetrad of states near 500 cm-1

Assignment of vibrational satellitesAssignment of vibrational satellites (using relative intensity, (using relative intensity,

statistical weights and inertial defects):statistical weights and inertial defects):Assignment of vibrational satellitesAssignment of vibrational satellites (using relative intensity, (using relative intensity,

statistical weights and inertial defects):statistical weights and inertial defects):

calc weight Inertial defect (uA2) (cm-1) obs. calc.

gs 0.49041(1) 0.480

4 122 A1 + 1.38528(2) 1.370

7 323 B1 - -0.79070(3) -0.852

8 366 B2 - 0.71380(3) 0.688

9 372 A2 + 1.00655(3) 1.131

3 496 A1 + 0.95354(5) 0.947

calc weight Inertial defect (uA2) (cm-1) obs. calc.

gs 0.49041(1) 0.480

4 122 A1 + 1.38528(2) 1.370

7 323 B1 - -0.79070(3) -0.852

8 366 B2 - 0.71380(3) 0.688

9 372 A2 + 1.00655(3) 1.131

3 496 A1 + 0.95354(5) 0.947

Weight denotes statistical weights relative to the ground state:

+ stands for unchanged

- denotes reversed weights

Calc results from uscaled B3LYP/6-31G(d,p)

ReassignedReassignedReassignedReassigned

Vibrational energy differences resulting from coupled fits Vibrational energy differences resulting from coupled fits

tetrad near 500 cm-1 :tetrad near 500 cm-1 :triad near 370 cm-1:triad near 370 cm-1:

Conclusions:Conclusions:Conclusions:Conclusions:

FASSST spectrum of S(CN)2 assigned, over 18000 lines measured and analysed resulting in:

Precise constants for the ground state and all 11 different vibrational excited states of the parent isotopomer for vibrational energy up to ca 500 cm-1

Constants for ground states of 34S and 13C isotopomers

Deviations of fits from 50 to 100 kHz

Confident assignment of first excited states of five different normal modes

Many precise vibrational energy level differences + …

Creation of highly efficient AABSAABS software package in order to manage data for many states simultaneously

UpdatedUpdatedUpdatedUpdated