FACULTY OF MATHEMATICS AND NATURAL SCIENCES PHYSICAL AND

FACULTY OF MATHEMATICS AND NATURAL SCIENCES PHYSICAL AND THEORETICAL CHEMISTRY 1 The general scheme of things Potential energy surface(s) Dipole moment surface(s). . . in general obtained from ab initio calculations Simulated rotation-vibration spectra PROGRAMS MORBID, RENNER, DR, TROVE

FACULTY OF MATHEMATICS AND NATURAL SCIENCES PHYSICAL AND THEORETICAL CHEMISTRY 2 Group 2 alkaline-earth M 2 O hypermetallic oxides

FACULTY OF MATHEMATICS AND NATURAL SCIENCES PHYSICAL AND THEORETICAL CHEMISTRY 3 Time evolution of the project

FACULTY OF MATHEMATICS AND NATURAL SCIENCES PHYSICAL AND THEORETICAL CHEMISTRY 4 Motivation ØStudy of molecular clusters as a way of understanding the emergence of crystalline properties from molecular properties. ØElucidation of the stability and structure of metal-rich clusters impacts on the development of new catalytic materials.

FACULTY OF MATHEMATICS AND NATURAL SCIENCES PHYSICAL AND THEORETICAL CHEMISTRY 5 General observation The molecules Be. OBe, Mg. OMg, and Ca. OCa studied ab initio thus far all have electronic ground states and lowlying electronic states.

FACULTY OF MATHEMATICS AND NATURAL SCIENCES PHYSICAL AND THEORETICAL CHEMISTRY 6 Ca. OCa ab initio calculation Ø Calculation of three-dimensional potential energy surface, and the electric dipole moment surfaces. Ø Multireference configuration interaction (MRCISD) approach in combination with internally contracted multireference perturbation theory (RS 2 C) based on full-valence complete active space selfconsistent field (FV-CASSCF) wavefunctions with a cc-pw. CVQZ-DK basis set for Ca and a ccp. CVQZ basis set for O.

FACULTY OF MATHEMATICS AND NATURAL SCIENCES PHYSICAL AND THEORETICAL CHEMISTRY Vibrational energies and B values for 40 Ca 16 O 40 Ca calculated by MORBID 7

FACULTY OF MATHEMATICS AND NATURAL SCIENCES PHYSICAL AND THEORETICAL CHEMISTRY 8 Simulated spectra of 40 Ca 16 O 40 Ca T = 15 K

FACULTY OF MATHEMATICS AND NATURAL SCIENCES PHYSICAL AND THEORETICAL CHEMISTRY 9 Comparison with 40 Ca 16 O-spectrum T = 15 K Fundamental band of 40 Ca 16 O n 3 band of -state 40 Ca 16 O 40 Ca has largest intrinsic intensity

FACULTY OF MATHEMATICS AND NATURAL SCIENCES PHYSICAL AND THEORETICAL CHEMISTRY Experiment? 10

FACULTY OF MATHEMATICS AND NATURAL SCIENCES PHYSICAL AND THEORETICAL CHEMISTRY 11 Experiment! Spectra resulting from reactions of 44 Ca with 16 O 3, and of 40 Ca with 16 O 3 and with 18 O 3. The infrared spectra of the reaction products, in the 15 K nitrogen matrix, were recorded in the 400– 800 cm− 1 region.

FACULTY OF MATHEMATICS AND NATURAL SCIENCES PHYSICAL AND THEORETICAL CHEMISTRY 12 Experiment! Strong peaks attributed to Ca. OCa by Andrews and Ault:

FACULTY OF MATHEMATICS AND NATURAL SCIENCES PHYSICAL AND THEORETICAL CHEMISTRY 13 Simulated spectra of 40 Ca 16 O 40 Ca T = 15 K No reasonable assignment possible!

FACULTY OF MATHEMATICS AND NATURAL SCIENCES PHYSICAL AND THEORETICAL CHEMISTRY 14 Simulated spectra of 40 Ca 16 O 40 Ca T = 15 K No reasonable assignment possible!

FACULTY OF MATHEMATICS AND NATURAL SCIENCES PHYSICAL AND THEORETICAL CHEMISTRY 15 Conclusion: Ø The spectra observed by Andrews and Ault are not due to Ca. OCa. Ø We hope that our calculations will assist in the eventual spectroscopic characterization of Ca. OCa.