Research and education in the Theory and Numerical Simulation of Condensed Matter group aim at advancing our understanding of how the microscopic constituents of matters self-assemble to bring about the whole complexity of the states of matter, from molecules to complex solids. The main research lines cover a wide spectrum of problems in condensed-matter physics ranging from the chemical physics of surfaces, interfaces, and nano-structured materials, to the properties of strongly correlated system and quantum fluids. The group comprises 9 faculty members, 10 postdoctoral fellows and 20 graduate students. The DEMOCRITOS Simulation Centre of the Istituto Officina dei Materiali (IOM) of National Council for Research (CNR), hosted by SISSA, is strongly integrated in the research activity of the Condensed Matter group. Strong links with scientists in the nearby Abdus Salam International Centre for Theoretical Physics (ICTP) and Elettra Synchrotron Radiation Facility are also present.