Cardiff School of Chemistry

Additional Information

PhD Università degli Studi di Milano (1995). Visiting Ph.D. student in the laboratory of Dr. James B. Anderson, Pennsylvania State University. CSRSRC-CNR (National Research Council) Post Doctoral Research Fellow (1997, positron chemistry). Post Doctoral Fellow, Dipartimento di Chimica Fisica, Università degli Studi di Milano (1998, quantum clusters). Research Scientist/Assistant, Dipartimento di Chimica Fisica, Università degli Studi di Milano (1998-2002). Junior Research Fellow, Wolfson College Oxford (2003-4). EPSRC Advanced Research Fellow, University of Oxford and Cardiff University (2002-7). Appointed as Lecturer in Theoretical Chemistry, Cardiff, in 2004.

Research Interests

• Development of classical and quantum methods to simulate molecular clusters, molecular and ionic liquids, and for the description of correlation effects in electronic structure calculations.
• Investigation of the static and dynamical properties of hydrogen bonded clusters and condensed phases, with emphasis on the systems relevant for atmospheric chemistry.
• Development of simulation methods for the calculation of exact reaction and dissociation rates.
• Investigation of the electronic structure, interaction and reactivity of positron containing compounds.
• Investigation of the energetic and transport properties of pure and doped quantum clusters.

Recent work within the Mella group has focussed mainly on three key topics: (i) the development of statistical simulation techniques for the description of the energetic and dynamics of molecular aggregates (either clusters or liquids); (ii) the generation of accurate model potentials describing interactions in molecular and ionic aggregates; and (iii) the study of systems for which quantum effects and correlated dynamics play a fundamental role in defining the properties.

The three investigation areas mentioned above represent different aspects of a wider research theme aiming toward the understanding of intermolecular forces and their effects on the properties of molecular aggregates of various sizes. This is of fundamental interest in many areas of science, allowing, for instance, the prediction of thermodynamical and transport properties of liquids, the investigation of the solubility of molecular species in super-fluid droplets, and to estimate the stability and lifetime of molecular aggregates such as pure and doped water clusters. The latter are of extreme relevance for the description of atmospheric phenomena involving solvated species or requiring acid catalysis to take place.

The theoretical investigation of these subjects requires the use of advanced computational tools such as high-level electronic structure theory and statistical/molecular dynamics simulations, as well as the development of conceptual models to describe the relationship between molecular and aggregate properties. Thus, the group is also involved in developing and improving a wide range of computational tools, going from quantum stochastic simulations for electronic structure calculations to advanced methods to extract exact reaction rates from molecular dynamics.

Further Information

Selected Publications

Massimo Mella, Gabriele Calderoni, Fausto Cargnoni, Predicting atomic dopant solvation in helium clusters: The MgHen case, J. Chem. Phys. 123 (2005) 054328, doi:10.1063/1.1982787

Massimo Mella, Improved importance sampling distribution for rate constant calculation, J. Chem. Phys. 122 (2005) 204106, doi:10.1063/1.1903903

Simone Chiesa, Quantum Monte Carlo estimators for the positron-electron annihilation rate in bound and low-energy scattering states, Phys. Rev. A 69 (2004) 022701, doi:10.1103/PhysRevA.69.022701

Massimo Mella, Zero temperature quantum properties of small protonated water clusters (H2O)nH+ (n = 1-5), J. Chem. Phys. 119 (2003) 10048, doi:10.1063/1.1618222