RESEARCH

Theoretical and computational condensed matter physics, with emphasis on ab-initio studies of solid surfaces and of bio/organic molecules interacting with the surfaces. Specific topics include:

• The role of equilibrium surface reconstructions in the epitaxial growth of widebandgap semiconductors (GaN and SiC). Surface reactions to the metallorganic precursors.
• Capabilities, limits, and extensions of solid state computational tools to biomolecules appealing for electronic applications. The investigated biomolecules are: (i) supramolecular assemblies of nucleotides, and (ii) copper metalloproteins.
• Theory of charge mobility in biomolecules: links between the solid-state-like charge transport through extended orbitals ad the charge transfer between localized molecular orbitals.
• DFT studies of the chemisorption of organic molecules and biomolecules on metal surfaces, in the diluted coverage range and in the range of self-assembled-monolayers: cysteine/Au(111) and mercaptobenzoxazole/Cu(100).

LIST OF PUBLICATIONS

1. A. Calzolari, G. Cicero, C. Cavazzoni, R. Di Felice, A. Catellani and S. Corni, "Protein specific adhesion on the gold surface in water by first principle simulations", submitted (2009).
2. A. Guijarro, O. Castillo, L. Welte, A. Calzolari, P. J. Sanz Miguel, C. J. Gómez-García, D. Olea, R. Di Felice, J. Gómez-Herrero, and F. Zamora, "MMX as conductors from single crystals to nanostructures", submitted (2009).
3. L. Welte, A. Calzolari, R. Di Felice, F. Zamora, and J Gómez-Herrero, "Highly conductive nanoribbons of coordination polymers", submitted (2009).
4. L. Nielsen, A. Holm, D. Varsano, U. Kadhane, S. Hoffmann, R Di Felice, A. Rubio and S. Nielsen "Fingerprints of bonding motifs in DNA duplexes of adenine and thymine revealed from circular dichroism: synchrotron radiation experiments and TDDFT calculations", J. Phys. Chem B 113, 9614 (2009).
5. A. Migliore, S. Corni, D. Varsano, M. L. Klein, and R. Di Felice "First-principles effective electronic couplings for hole transfer in natural and size-expanded DNA", J. Phys. Chem. B 113, 9402 (2009).
6. D. Varsano, L. A. Espinosa-Leal, X. Andrade, M. A. L. Marques, R. Di Felice, and A. Rubio, "A gauge invariant method for molecular chiroptical properties in TDDFT", Phys. Chem. Chem. Phys. 11, 4481 (2009).
7. R. de Paiva and R. Di Felice, "Electronic structure of Au/CdSe(0001) and Au/CdSe(0001) interfaces", ACS Nano 2, 2225 (2008).
8. D.A. Ryndyk, E. Shapir, D. Porath, A. Calzolari, R. Di Felice, and G. Cuniberti,"Scanning Tunneling Spectroscopy of Single DNA Molecules"", ACSnano 3, 1651 (2009).
9. F. Iori, R. Di Felice, E. Molinari, and S. Corni "GolP: An Atomistic Force-Field to Describe the Interaction of Proteins With Au(111) Surfaces in Water", J. Comput. Chem. 30, 1465 (2009).
10. G. Brancolini and R. Di Felice, "Electronic properties of metal-modified DNA base pairs", J. Phys. Chem. B 112, 14281 (2008).
11. F. Iori, S. Corni, and R. Di Felice "Unraveling the Interaction between Histidine Side Chain and the Au(111) Surface: A DFT Study", J. Phys. Chem. C 112, 13540 (2008).
12. A. Guijarro, Os. Castillo, A. Calzolari, P. J. Sanz Miguel, C. J. Gómez-García, R. di Felice, and F. Zamora, "Electrical conductivity in Platinum-dimer columns", Inorg. Chem. 47, 9736 (2008).
13. A. Calzolari, R. Di Felice, S.S. Alexander, and F. Zamora, "Metallicity in individual MMX chains", J. Am. Chem. Soc. 130, 5552 (2008).
14. E. Shapir, H. Cohen, A. Calzolari, C. Cavazzoni, D. A. Ryndyk, G. Cuniberti, A. Kotlyar, R. Di Felice and D. Porath, "Electronic structure of single DNA molecules resolved by transverse scanning tunneling spectroscopy", Nat. Mater. 7, 68 (2008).
15. D. Varsano, A. Garbesi and R. Di Felice, "Ab initio optical absorption spectra of size-expanded xDNA base assemblies", J. Phys. Chem. B 111, 14012 (2007).
16. C. Baldacchini, C. Mariani, M.G. Betti, I. Vobornik, J. Fujii, E. Annese, G. Rossi, A. Ferretti, A. Calzolari, R. Di Felice, A. Ruini, E. Molinari, "Symmetry lowering of pentacene molecular states interacting with a Cu Surface", Phys. Rev. B 76, 245430 (2007).
17. A. Setty-Venkat, S. Corni, R. Di Felice, “Electronic ccoupling between Azurin and Gold at different protein/substrate orientations”, Small 3, 1431 (2007).
18. H. Cohen, T. Sapir, N. Borovok, T. Molotsky, R. Di Felice, A. B. Kotlyar, and D. Porath, “Polarizability of G4-DNA Observed by EFM measurements”, Nano Lett. 7, 981 (2007).
19. A. Migliore, S. Corni, R. Di Felice, and E. Molinari, “Water-mediated electron transfer between protein redox centers”, J. Phys. Chem. B 111, 3774 (2007).
20. A. Migliore, S. Corni, R. Di Felice, and E. Molinari, “Water Effects on Electron Transfer in Azurin Dimers”, J. Phys. Chem. B, 110, 23796 (2006).
21. A. Ferretti, C. Baldacchini, A. Calzolari, R. Di Felice, A. Ruini, E. Molinari, and M. G. Betti, "Mixing of electronic states in pentacene adsorption on copper", Phys. Rev. Lett. 99, 046802 (2007).
22. R. Di Felice, “DNA-based Nanoelectronics”, invited chapter to be published in “Nanobioelectronics for electronics, biology and medicine”, A. Offenhauser and R. Rinaldi eds., Springer series “Nanostructure Science and Technology”, 2006.
23. R. Di Felice and D. Porath, “DNA-based Nanoelectronics”, invited chapter to be published in “NanoBioTechnology: BioInspired devices and materials of the future”, O. Shoseyov and I. Levy eds., Humana Press, Totowa (NJ, USA), 2006.
24. A. Calzolari and R. Di Felice, "Surface functionalization through adsorption of organic molecules", J. Phys.: Cond Matt. 19, 305018 (2007).
25. A. Ferretti, A. Calzolari, B. Bonferroni, R. Di Felice, "Maximally localized Wannier functions from PAW or ultrasoft pseudopotentials", J. Phys.: Condens. Matter 19, 036215 (2007).
26. M. Petrilli, S. Corni, and R. Di Felice, “Hyperfine and electronic properties in Azurin by means of PAW DFT calculations”, submitted (2005).
27. D. Varsano, R. Di Felice, M. A. L. Marques, and A. Rubio, “A TDDFT study of excited states of DNA bases and base assemblies”, J. Phys. Chem. B 110, 7129 (2006).
28. M. Cavallari, A. Calzolari, A. Garbesi, and R. Di Felice, "Stability and Migration of Metal Ions in G4-wires by Molecular Dynamics Simulations", J. Phys. Chem B 110, 26337 (2006).
29. R. Di Felice and A. Calzolari, “Electronic structure of DNA derivatives and mimics by Density Functional Theory”, in “'Modern methods for theoretical physical chemistry of biopolymers”, pp. 485-507, ed. by Evgeni B. Starikov, James P. Lewis and Shigenori Tanaka, Elsevier (2006).
30. A. Migliore, S. Corni, R. Di Felice, and E. Molinari, "First-Principles DFT Calculations of Electron Transfer Rates in Azurin Dimers”, J. Chem. Phys. 124, 064501 (2006)
31. R. Di Felice, A. Calzolari, A. Garbesi, S. S. Alexandre, and J. M. Soler, "Strain-dependence of the electronic properties in periodic quadruple helical G4-wires", J. Phys. Chem. B 109, 22301(2005).
32. A. Ferretti, A. Calzolari, R. Di Felice, F. Manghi, "First principles theoretical description of transport including electron-electron correlation, Phys. Rev. B 72, 125114 (2005).
33. A. Bramanti, P.P. Pompa, G. Maruccio, F. Calabi, V. Arima, R. Cingolani, R. Rinaldi, S. Corni, R. Di Felice, and F. De Rienzo, “Azurin for Biomolecular Electronics: a Reliability Study”, Jap. J. Appl. Phys. 44, 6864 (2005) .
34. P. P. Pompa, A. Bramanti, G. Maruccio, R. Cingolani, F. De Rienzo, S. Corni, R. Di Felice, and R. Rinaldi, “Retention of native-like conformation by proteins embedded in high external electric fields”, J. Chem. Phys. 122, 181102 (2005).
35. C. Sbraccia, C. A. Pignedoli, A. Catellani, R. Di Felice, P. L.Silvestrelli, F. Toigo, F. Ancilotto, and C. M. Bertoni, "Acetilene on Si(111) from computer simulations", Comput. Phys. Comm. 169, 32 (2005).
36. R. Di Felice and S. Corni, "Computational approach to study electron-transfer proteins: Azurin for bio-molecular devices", Computer Physics Comm. 169, 9 (2005).
37. H. Zhang, A. Calzolari, and R. Di Felice, "Ferromagnetic alignment of metal ions in a DNA-mimic double helix", J. Phys. Chem. B 109, 15345 (2005).
38. M.C. Righi, C.A. Pignedoli, R. Di Felice, C.M. Bertoni, and A. Catellani, "Kinetic Monte Carlo simulations of C diffusion on \sqrt{3}x\sqrt{3} beta-SiC(111) based on ab-initio calculations", Comput. Phys. Comm. 169, 50 (2005).
39. G. Maruccio, A. Biasco, P. Visconti, A. Bramanti, P.P. Pompa, F. Calabi, R. Cingolani, R. Rinaldi, S. Corni, R. Di Felice, and E. Molinari, "Towards protein field-effect transistors: report and model of a prototype", Adv. Mater. 17, 816 (2005).
40. R. Di Felice, C. M. Bertoni, C. A. Pignedoli, and A. Catellani, “Hydrogen induced metallization of beta-SiC(100)-(3x2) revisited by means of first principles calculations”, Phys. Rev. Lett. 94, 116103 (2005).
41. A. Ferretti, A. Calzolari, R. Di Felice, F. Manghi, M.J. Caldas, M. Buongiorno Nardelli, and E. Molinari, "First principle theory of correlated transport through nano-junctions", Phys. Rev. Lett. 94, 116802 (2005).
42. R. Di Felice, A. Rubio Secades, D. Varsano, and A. Calzolari, "Electronic structure calculation for nanomolecular systems", invited paper to be published in "Introducing Molecular Electronics" edited by G. Cuniberti, K. Richter G. Fargas , Lect. Notes Phys. 680, 77 (2005). (Springer ).
43. A. Ferretti, and R. Di Felice, "Electron delocalization at the hybrid aromatic-thiol/Cu(100) interface", Phys. Rev. B. 70, 115412 (2004).
44. S. Corni, R. Di Felice, and E. Molinari, "On the electronic structure analysis for one redox-active molecule", Chem Phys. Lett. 393, 118 (2004).
45. M.C. Righi, C.A. Pignedoli, R. Di Felice, A. Catellani, and C.M. Bertoni, "Combined ab initio and kinetic Monte Carlo simulation of c diffurion on Sqrt(3)xSqrt(3) beta-SiC(111) surface, Phys. Rev. B 71, 075303 (2005).
46. S. Corni, F. De Rienzo, R. Di Felice, and E. Molinari, "Redox activity at the Azurin active site by means of ab-initio electronic structure calculations", Int. J. Quantum Chem. 102, 328 (2005).
47. R. Di Felice, A. Calzolari, H. Zhang, "Towards metalated DNA-based structures", Nanotechnology. 15, 1256 (2004).
48. V. Yu. Aristov, P. Soukiassian, A. Catellani, R. Di Felice, G. Galli, "Experimental and theoretical electronic structure determination of the beta-SiC(001)c(4 x 2) surface reconstruction", Phys. Rev. B 69, 245326 (2004).
49. C. Sbraccia, C. A. Pignedoli, A. Catellani, R. Di Felice, P. L. Silvestrelli, F. Toigo, F. Ancilotto, and C. M. Bertoni, “Chemisorption sites and reaction pathways for acetylene on Si(111)-7x7)”, Surf. Sci. 557, 80 (2004).
50. A. Calzolari, R. Di Felice, and E. Molinari, "Electronic properties of guanine-based nanowires", Sol. St. Commun. 113, 577 (2004) - Special Issue on "New advances on collective phenomena in one-dimensional systems", Ed. by H. Grabert and V. Pellegrini.
51. R. Di Felice, A. Ferretti, C. Mariani, M.G. Betti, C. Baldacchini, V. Di Castro, "Surface-Science Approach to the Study of Mercaptobenzoxazole on Cu(100)", Surf. Sci. 566-568, 579 (2004).
52. C. A. Pignedoli, R. Di Felice, C. M. Bertoni, "Surface Effects in GaN Growth", Surf. Sci. 547, 63 (2003)
53. R. Di Felice and A. Selloni, "Adsorption Modes of Cysteine on Au(111): Thiolate, Amino-Thiolate, Disulfide", J. Chem. Phys. 120, 4906 (2004).
54. A. Calzolari, R. Di Felice, E. Molinari, and A. Garbesi, "Electron channels in biomolecular nanowires", J. Phys. Chem. B 108, 2509 (2004). Correction: J. Phys. Chem. B 108, 13058 (2004).
55. V. De Renzi, R. Di Felice, D. Marchetto, R. Biagi, U. Del Pennino, A. Selloni, "Ordered (3x4) High Density Phase of Methylthiolate on Au(111)", J. Phys. Chem. B. (Lett.) 108, 16 (2004).
56. M. C. Righi, C. A. Pignedoli, A. Catellani, R. Di Felice, and C. M. Bertoni, "Ab initio simulations of homoepitaxial SiC growth", Phys. Rev. Lett. 91, 136101 (2003).
57. Danny Porath, Gianaurelio Cuniberti, Rosa Di Felice, "Charge Transport in DNA-based Devices", in "Long Range Charge Transfer in DNA", ed. Gary Schuster, Topics in Current Chemistry 237, p. 183-227, Springer-Verlag, Heidelberg (2004).
58. R. Di Felice, A. Selloni, and E. Molinari, "A DFT study of cysteine adsorption on Au(111)", J. Phys. Chem B 107, 1151 (2003).
59. R. Rinaldi, A Biasco, G. Maruccio, R. Cingolani, D. Alliata, L. Andolfi, P. Facci, F. De Rienzo , R. Di Felice, E. Molinari, M. Verbeet and G. Canters, "Electronic rectification in protein devices", Appl. Phys. Lett. 82, 472 (2003).
60. R. Di Felice, C. A. Pignedoli, C. M. Bertoni, A. Catellani, P. L. Silvestrelli, C. Sbraccia, F. Ancilotto, M. Palummo, and O. Pulci, "Ab-Initio Investigation of the Adsorption of Organic Molecules at Si(111) and Si(100) Surfaces", Surf. Sci. 532-535, 982 (2003).
61. R. Rinaldi, A. Biasco, G. Maruccio, R. Cingolani, D. Alliata, L. Andolfi, P. Facci, F. De Rienzo, R. Di Felice, and E. Molinari, "Solid state molecular rectifier based on self organized metalloproteins", Adv. Mat. 14, 1453 (2002).
62. M.C. Righi, C.A. Pignedoli, G. Borghi, R. Di Felice, C.M. Bertoni, and A. Catellani, "Surface induced stacking transition at SiC(0001)", Phys. Rev. B 66, 045320 (2002).
63. A. Calzolari, R. Di Felice, E. Molinari, and A. Garbesi, "G-Quartet Biomolecular Nanowires", Appl. Phys. Lett. 80, 3331 (2002).
64. A. Calzolari, R. Di Felice, E. Molinari, and A. Garbesi, "Self-assembled guanine ribbon as wide-bandgap semiconductors", Physica E 13, 1236 (2002).
65. R. Rinaldi, E. Branca, R. Cingolani, R. Di Felice, A. Calzolari, E. Molinari, S. Masiero, G.P. Spada, G. Gottarelli, and A. Garbesi, "Biomolecular electronic device based on Self-organized Deoxyguanosine nanocrystals", pp 184-192, in "Molecular Electronics II", edited by A. Aviram, M. Ratner, V. Mujica, Annals of the New York Academy of Science (Vol. 60), April 2002.
66. R. Di Felice, A. Calzolari, E. Molinari, and A. Garbesi, "Ab-initio study of model guanosine assemblies: The role of pi-pi coupling and band transport", Phys. Rev. B 65, 045104 (2002).
67. C. A. Pignedoli, R. Di Felice, and C. M. Bertoni, "Dissociative chemisorption of NH_3 molecules on GaN(0001) surfaces " Phys. Rev. B 64, 113301 (2001).
68. A. Calzolari, C.A. Pignedoli, R. Di Felice, C.M. Bertoni, and A. Catellani, "Theory of Cs adsorption on InAs(110)", Surf. Sci. 491, 265 (2001).
69. C.A. Pignedoli, R. Di Felice, and C.M. Bertoni, "The dissociative chemisorption of NH3 molecules in the frame of GaN growth", Proc. 25th Int. Conf. Phys. Semicond., Osaka 2000, pp. 1499-1500, edited by N. Miura and T. Ando, Springer (2001).
70. R. Di Felice, and J.E. Northrup, "Theory of Al2O3(0001) surfaces and their employment as a substrate for nitride growth", Proc. 25th Int. Conf. Phys. Semicond., Osaka 2000, pp. 281-282, edited by N. Miura and T. Ando, Springer (2001).
71. R. Rinaldi, E. Branca, R. Cingolani, R. Di Felice, E. Molinari, S. Masiero, G.P. Spada, G. Gottarelli, and A. Garbesi, "Electronic characteristics of a DNA-based nanogate", Proc. 25th Int. Conf. Phys. Semicond Osaka 2000, edited by N. Miura and T. Ando, Springer Berlin (2001).
72. C. M. Bertoni, G. Roma, and R. Di Felice, Electronic Structure of Adsorbates on Surfaces. Adsorption on Semiconductors., in Handbook of Surfaces II, pp. 247-283, editors M. Scheffler and K. Horn, Elsevier, March 2000.
73. U. Hohenester, R. Di Felice, E. Molinari, and F. Rossi, Microscopic Theory of the Excitonic Absorption of In_{x}Ga_{1-x}N Quantum Dots in In_{y}Ga_{1-y}N Layers, Physica E 7, 934 (2000).
74. A. Calzolari, C. A. Pignedoli, R. Di Felice, C. M. Bertoni, and A. Catellani, First-principle investigation of the formation of Cs-dimer-chains upon adsorption on InAs(110), Surf. Sci. 454-456, 207 (2000).
75. A. Catellani and R. Di Felice, Early stages of deposition of nitrides on cubic silicon carbide: a theoretical study, Phys. Stat. Sol. (a) 177, 99 (2000).
76. R. Di Felice and J. E. Northrup, Theory of the clean and hydrogenated Al_{2}O_{3}(0001)-(1x1) surfaces, Phys. Rev. B 60, R16287 (1999).
77. U. Hohenester, R. Di Felice, E. Molinari, and F. Rossi, Optical spectra of nitride quantum dots: quantum confinement and electron-hole coupling, Appl. Phys. Lett. 75, 3449 (1999).
78. R. Di Felice, C. M. Bertoni, and A. Catellani, First-principles study of beta-AlN thin films on beta-SiC(001), Appl. Phys. Lett. 74, 2137 (1999).
79. R. Di Felice and J. E. Northrup, Energetics of AlN thin films on the Al_{2}O_{3}(0001) surface, Appl. Phys. Lett. 73, 936 (1998).
80. C. M. Bertoni, R. Di Felice, and C. A. Pignedoli, First-principles simulations of molecular processes at semiconductor surfaces, Il Nuovo Cimento 20, 967 (1998).
81. R. Di Felice and J. E. Northrup, Theory of the AlN/SiC(10-10) interfaces, Phys. Rev. B 56, 9213 (1997).
82. J. E. Northrup, R. Di Felice, and J. Neugebauer, Energetics of H and NH_{2} on GaN(10-10) and implications for the origin of nanopipe defects, Phys. Rev. B 56, R4325 (1997).
83. J. E. Northrup, R. Di Felice, and J. Neugebauer, Atomic structure and stability of AlN(0001) and (000-1) surfaces, Phys. Rev. B 55, 13878 (1997).
84. R. Di Felice, J. E. Northrup, and J. Neugebauer, Energetics of AlN thin films and the implications for epitaxial growth on SiC, Phys. Rev. B 54, R17351 (1996).
85. R. Di Felice, J. E. Northrup, and J. Neugebauer, Energetics of AlN epitaxial wetting layers on SiC(0001), published in: III-V Nitrides, MRS Symposia Proceedings 449, edited by T. Moustakas, B. Monemar, I. Akasaki, and F. Ponce (MRS, Pittsburgh, Pennsylvania, 1996).
86. R. Di Felice, M. L. Mantovani, and C. M. Bertoni, Ab-initio Molecular Dynamics calculations: a parallel implementation of the Car-Parrinello method, Proceedings of the 4^{th} Euromicro Workshop on Parallel and Distributed Processing, Braga, Portugal (1996).
87. A. I. Shkrebtii, R. Di Felice, C. M. Bertoni, and R. Del Sole, Ab-initio study of structure and dynamics of the Si(100) surface, Phys. Rev. B 51, R11201 (1995).
88. C. M. Bertoni and R. Di Felice, Basic Principles of Surface Science, Surf. Rev. and Lett. 2, 817 (1995).
89. A. I. Shkrebtii, C. M. Bertoni, R. Di Felice, and R. Del Sole, Atomic and Electronic Structure, Phonons and Optical Properties of Si(100) at 300 K and 900 K, Proceedings of the 22^{nd} International Conference on the Physics of Semiconductors, Vancouver, Canada (1994).
90. R. Di Felice, A. I. Shkrebtii, F. Finocchi, C. M. Bertoni, and G. Onida, Surface vibrations at clean and hydrogenated GaAs(110) from ab-initio molecular dynamics, J. of Electr. Spectr. and Rel. Phen. 64/65, 697 (1993).
91. C. M. Bertoni, A. I. Shkrebtii, R. Di Felice, and F. Finocchi, Structural and Dynamical Properties of Surfaces From ab-initio Molecular Dynamics, Progr. in Surf. Sci. 42, 319 (1993).
92. R. Di Felice, A. I. Shkrebtii, F. Finocchi, and C. M. Bertoni, Structural, Dynamical and Electronic Properties of Clean and Hydrogenated GaAs(110) Surfaces from ab-initio Molecular Dynamics'', Proceedings of the 21^{st} International Conference on the Physics of Semiconductors, Beijing, China (1992).
93. M. Buongiorno Nardelli, F. Finocchi, M. Palummo, R. Di Felice, C. M. Bertoni, F. Bernardini, and S. Ossicini, Hydrogen covered Si(111) surfaces, Surf. Sci. 269/270, 879 (1992).

OTHER PUBLICATIONS

• A. Calzolari, R. Di Felice, and C. Cavazzoni, "Ultrafreddo e simulazioni per esplorare la struttura elettronica del DNA", Notizie dal CINECA 60, 3 (2008); cover - text
• R. Di Felice, M.C. Righi, C.A. Pignedoli, C.M. Bertoni, A. Catellani, “First principles description of C, Si, and H adsorption on b-SiC surfaces”, Science and Supercomputing at CINECA – Report 2005, pg. 443 (2006).
• R. Di Felice, A. Calzolari, H.Y. Zhang, M. Cavallari, E. Molinari, A. Garbesi, “Simulation of DNA derivatives and mimics”, Science and Supercomputing at CINECA – Report 2005, pg. 643 (2006).
• R. Di Felice and D. Porath, “Visions in Bio-Molecular Nano-Electronics in FP7”, E-nano Newsletter 3, 9 (2006). http://www.phantomsnet.net