Guido L. Chiarotti (GC) was born in Pavia in 1960. He started its scientific activity in 1984 as associated scientist at Argonne National Laboratory (Argonne, Illinois). There, under the guidance of Anees Rahman, one the father of Computer Simulations, he was involved in a project on the study of dynamical properties of AgI. In 1986 GC has joined the Car-Parrinello SISSA group with a postdoctoral fellowship, and has partecipated to both the development of the Car-Parrinello method and to its applications to a variety of problems in condensed matter physics, including diffusive properties, amorphous and liquid systems, surface physics. Since 1991 GC is coordinating the activity of the First Principles Molecular Dynamics SISSA group. He joned the SISSA permanent staff in june 1992, and is presently a member of the Administration Council of the School. He is teaching the First Principles Molecular Dynamics course to first year condensed matter PhD students. Recently, in collaboration with P. Focher, M. Bernasconi, E. Tosatti and M. Parrinello, GC has extended the original Car-Parrinello method to constant-pressure variable-cell simulations opening to first principles simulations the very relevant field of high-pressure phisycs.