Jet Propulsion Laboratory (JPL), Pasadena, CA, USA

From spring 1995 to summer 1997 I obtained a stipend from the National Research Council to work at the Jet Propulsion Laboratory (JPL), Pasadena, CA, USA, as a NASA-NRC Resident Research Associate. While you may well know that JPL is heavily involved in NASA's unmanned space missions, it also an important place for Earth sciences, including atmospheric chemistry. I used submillimeter and millimeter spectroscopy to investigate molecules of atmospheric interest, often in collaboration with Dr. Edward A. Cohen.

The first high resolution spectra of Br2O, OBrO, and ClClO2 have been obtained and analyzed. The spectroscopic constants were used to derive structural parameters and harmonic force constants and to gain insight into the halogen bonds from the hyperfine constants.

Further projects were, e. g., the investigations of ClONO2 (chlorine nitrate) and OClO. For the latter molecule, an anharmonic (quartic) force field was derived in collaboration with G. Ole Sørensen. I also contributed to the JPL submillimeter, millimeter, and microwave catalog which contains line features for atmospheric chemists and radioastronomers.

Publications related to work in Pasadena

  1. H. S. P. Müller, C. E. Miller, and E. A. Cohen,
    Dibrommonoxid, Br2O, und Bromdioxid, OBrO: spektroskopische Eigenschaften, Molekülstrukturen, und harmonische Kraftfelder,
    Angew. Chem. 108 (1996) 2285 – 2288;
    Dibromine Monoxide, Br2O, and Bromine Dioxide, OBrO: Spectroscopic Properties, Molecular Structures, and Harmonic Force Fields,
    Angew. Chem. Int. Ed. Engl. 35 (1996) 2129 – 2131.
  2. J. C. Pearson and H. S. P. Müller,
    The Submillimeter-Wave Spectrum of Isotopic Methyl Cyanide,
    Astrophys. J. 471 (1996) 1067 – 1072.  View abstract
  3. H. S. P. Müller, P. Helminger, and S. H. Young,
    Millimeter and Submillimeter Spectroscopy of Chlorine Nitrate: The Cl Quadrupole Tensor and the Harmonic Force Field,
    J. Mol. Spectrosc. 181 (1997) 363 – 378.  View abstract
  4. H. S. P. Müller and E. A. Cohen,
    The Submillimeter Spectrum and Structure of Chloryl Chloride, ClClO2,
    J. Phys. Chem. A 101 (1997) 3049 – 3051.  View abstract
  5. H. S. P. Müller and E. A. Cohen,
    Dibromine Monoxide, Br2O: the Rotational Spectrum and Molecular Properties,
    J. Chem. Phys. 106 (1997) 8344 – 8354.  View abstract
  6. H. S. P. Müller, C. E. Miller, and E. A. Cohen,
    The Rotational Spectrum and Molecular Properties of Bromine Dioxide, OBrO,
    J. Chem. Phys. 107 (1997) 8292 – 8302.  View abstract
  7. H. S. P. Müller, G. O. Sørensen, M. Birk, and R. R. Friedl,
    The Rotational Spectrum and Anharmonic Force Field of Chlorine Dioxide, OClO,
    J. Mol. Spectrosc. 186 (1997) 177 – 188.  View abstract
  8. H. M. Pickett, R. L. Poynter, E. A. Cohen, M. L. Delitsky, J. C. Pearson, and H. S. P. Müller,
    Submillimeter, Millimeter, and Microwave Spectral Line Catalog,
    J. Quant. Spectrosc. Radiat. Transfer 60 (1998) 883 – 890.  View abstract
  9. H. S. P. Müller, E. A. Cohen, and D. Christen,
    The Rotational Spectrum of Chloryl Chloride, ClClO2, in its Ground Vibrational State,
    J. Chem. Phys. 110 (1999) 11865 – 11875.  View abstract
  10. H. S. P. Müller,
    Rotational and Vibrational Spectra of Chloryl Fluoride, FClO2. Nuclear Quadrupole, Spin-Rotation, and Shielding Tensors and the Harmonic Force Field,
    J. Mol. Struct. 517–518 (2000) 335 – 350.  View abstract
  11. H. S. P. Müller, J. Farhoomand, E. A. Cohen, B. Brupbacher-Gatehouse, Martin Schäfer, Alfred Bauder, and Gisbert Winnewisser,
    The Rotational Spectrum of SO2 and the Determination of the Hyperfine Constants and Nuclear Magnetic Shielding Tensors of 33SO2 and SO17O,
    J. Mol. Spectrosc. 201 (2000) 1 – 8.  View abstract
  12. B. J. Drouin, C. E. Miller, H. S. P. Müller, and E. A. Cohen,
    The Rotational Spectra, Isotopically Independent Parameters, and Interatomic Potentials for the X1 2Π3/2 and X2 2Π1/2 States of BrO,
    J. Mol. Spectrosc. 205 (2001) 128 – 138.  View abstract
  13. H. S. P. Müller,
    The Rotational Spectrum of Chlorine Trifluoride, ClF3. Centrifugal Distortion Analysis, Cl Nuclear Magnetic Shielding Tensor, Structure, and the Harmonic Force Field,
    Phys. Chem. Chem. Phys. 3 (2001) 1570 – 1575.  View abstract
  14. J.-M. Flaud, H. S. P. Müller, and H. Bürger,
    High-Resolution Infrared, Microwave, and Submillimeter-Wave Study of FClO2 in the v2, v3, v4, and v6 Excited States,
    J. Mol. Spectrosc. 207 (2001) 216 – 223.  View abstract
  15. H. S. P. Müller and E. A. Cohen,
    The Molecular Properties of Chlorosyl Fluoride, FClO, as Determined from its Ground-State Rotational Spectrum,
    J. Chem. Phys. 116 (2002) 2407 – 2416.  View abstract
  16. H. S. P. Müller, E. A. Cohen, and D. Christen,
    The Rotational Spectrum of ClClO2 in its v4 = 1 and v6 = 1 Vibrationally Excited States: An Example of Strong Coriolis Interaction,
    J. Mol. Spectrosc. 216 (2002) 335 – 344.  View abstract
  17. E. A. Cohen, H. S. P. Müller, T. L. Tan, and G. A. McRae,
    High Resolution Spectroscopy of DOBr and Molecular Properties of Hypobromous Acid
    J. Mol. Spectrosc. 262 (2010) 30 – 36.  View abstract.