Professor M.S. Child

Physical & Theoretical Chemistry Laboratory

Email Address: mark.child@chem.ox.ac.uk

Telephone: 44 (0) 1865 275 151

Research Group Web Site

My research develops new theories for the interpretation and prediction of complex intramolecular processes.

1. Rydberg Spectrocopy of polyatomic molecules

Modern VUV and XUV high resolution laser studies of molecular Rydberg states present a new challenge for theoretical spectroscopy. Interesting features include (i) breakdown of the Born-Oppenheimer approximation as the electronic energy separation becomes comparable even to rotational energy spacings, (ii) aoutoionization arising from inelastic scattering of th electron from the positive ion core, and (iii) new predissociation mechanisms. The aim is to develop a comprehensive theory of these diverse effects, by combining analytical and numerical scattering techniques.

2. Semiclassical theories of complex intramolecular dynamics

 Semiclassical methods aim to relate quantum mechanical observables to the underlying classical mechanics. Specific examples include early work on local mode states of small hydrides and interference effects on predissociation rates.. More recently, similar methods point to a characteristic pattern in quantum energy levels close to saddle points – now taken as an example of so-called ‘quantum monodromy.

Books

1. M. S. Child, Semiclassical Mechanics with Molecular Applications (Oxford, 1991)
2. M. S. Child, Molecular Collision Theory (Dover, 1996)

Selected recent publications

• M.S. Child, T. Weston and J. Tennyson, Quantum monodromy in the spectrum of H2O and other species: new insight into the quantum level structure of quasi-linear molecules, Mol. Phys., 96, 371 (1999).
• Child, M.S. and Glab, W.L. ‘Multichannel quantum defect analysis of the double resonance photoionization series of H2O.’ J.Chem.Phys. 112, 3754-3765. (1999).
• Jacobson, M.P.  and Child, M.S. ‘Spectroscopic signatures of bond-breaking internal rotation I Saddle point induced polyad breakdown’, J.Chem.Phys. 114, 250-261 (2001)
• Shalashilin, D.V. and Child, M.S. ‘Multidimensional quantum propagation with the help of coherent states’, J.Chem.Phys. 115, 5367, (2001).
• Hiyama, M. and Child, M.S. ‘Ab initio R-matrix/multichannel quantum defect theory study of nitric oxide’, J.Phys.B: At.Mol.Opt.Phys. 35, 1337-1351 (2002).
• Shalashilin, D.V. and Child, M.S., ;’Nine-dimensional quantum molecular dynamics simulation of intramolecular vibrational energy redistribution in the CHD3 molecule with the help of coupled coherent states’, J.Chem.Phys. 119, (4) : 1961-1969 (2003).
• Cooper, C.D. and Child M. S., ‘Quantum level structures at a Fermi resonance, with angular momentum: classical periodic orbits, catastrophe maps and quantum monodromy’, Phys. Chem. Chem. Phys., 7, 2731-2739 (2005).