He was a dear friend to all of us, and a most valuable scientific collaborator.
We want to give here an account of his activity in our group.
Alessio joined our group as a student of Materials Science in 2004, while preparing his bachelor (3-year) thesis concerning the quantum-mechanical simulation of oxide epi-layers on metals (in particular, Nickel Oxide on Silver) with the supervision of Professor Cesare Pisani and in collaboration with Professor Anna Ferrari. The same problem with the same supervisor, but at a higher level of analysis, was later the object of his master (5-year) thesis which he defended in 2007. In both cases, he was promoted with honors. While performing the theoretical simulations, he had the opportunity to interact with scientists at the Padua University (Professor Gaetano Granozzi, Doctor Stefano Agnoli) who were investigating the same systems experimentally. His fruitful sojourns in that Laboratory and the seminars he gave there are still in the memory of those people. The competence he acquired in the subtle problems analyzed in his theses, and concerning a system with a „mixed“ (conducting-insulating) character, allowed him to produce first-hand, very interesting data which were included in the monograph Periodic ab initio simulation of oxide epi-layers on simple metal surfaces, published as Chapter 1 in an important book edited by Professors Vladimir Basiuk and Piero Ugliengo .
After winning a Doctorate bursary, his interests were addressed to quite different subjects. Under the supervision of Professor Roberto Dovesi, he was mainly involved in the development, application, and test of new features of the CRYSTAL program. This activity meant studying and implementing new algorithms, and testing them with a variety of problems, often never explored before. In this field, Alessio proved again a reliable, enthusiastic and clever collaborator.
An incomplete list of the subjects he addressed includes (in parentheses, the corresponding keywords in the new public version of the code, CRYSTAL09):
a) dual basis option, which permits the progressive improvement of the basis set, by recovering information from previous CRYSTAL calculations (GUESDUAL);
b) f and d orbitals guess (FDOCCUP) and f and d degeneracy analysis (FDAOSYMM);
c) tools for the symmetry analysis of solid solutions, and their investigation (CEM);
d)implementation of the calculation of the IR intensity through the Berry phase approach(INTPOL);
e) study of the structural, vibrational, dielectric and magnetic properties of garnets (pure crystals and solid solutions);
f) study and all-electron basis set optimisation of lanthanides;
The list below documents his rich activity: papers (a few more are still under scrutiny), chapters, seminars, posters, tutorials.
WORKSHOP AND CONGRESS CONTRIBUTIONS
1) “Ab-initio periodic simulation of the electronic and magnetic structure of garnets containing transition metals with a local basis set approach”, Alessio Meyer, European Conference on Computational Chemistry, S. Servolo, Venezia, September 11-15 2008
2) contribution to: “The role of charge and spin density in the quantum mechanical simulation of crystalline solids. The case of X3Y2Si3O12 garnets”, Roberto Dovesi, 5th European charge density meeting, Gravedona (CO), 6 -11 June 2008
3) “Cluster expansion mapping of ab initio calculations: an application to solid solutions”, Alessio Meyer, CECAM workshop Structural transitions in solids, Lugano , 8-1 July 2009
4) “Combinatorial mapping of solid solutions and magnetic configurations”, Alessio Meyer, MSSC2009 - Ab initio Modelling in Solid State Chemistry, University of Torino, Torino (IT), 6-12 September 2009
1)“Periodic ab initio simulation of garnets containing transition metals with a localized basis set approach”, Alessio Meyer, “Accurate energetics of condensed matter with quantum chemistry” CECAM, Lyon, May 26-29 2008
2)“Periodic ab initio simulation of garnets containing transition metals with a localized basis set approach”, Alessio Meyer, “Simulation of crystalline systems: history and prospects, workshop in honour of Prof. Cesare Pisani”, Torino, September 9-11 2008
3)“Ab intitio simulation of magnetic properties of Uvarovite and Andradite garnets”, “Computational Magnetism and spintronics”, Alessio Meyer, Max Planck Institute, Dresden, November 3-7 2008
4) “ Magnetic structure of gemanates garnets” Alessio Meyer, Psi-k Workshop on Magnetis in Complex Systems Vienna University of Technology, Vienna, 16 – 19 April 2009
5) contribution to: “Ab initio modeling of oxydated and hydrogenated diamond surfaces by means of an all-electron basis set/hybrid Hamiltonian approach”, Marco De La Pierre, DIAMOND 2009 – 20th European Conference on Diamond, Diamond Like Materials, Carbon Nanotubes, and Nidrides, Athens (GR), 6-10 September 2009