  Since electronic and magnetic properties of many transition-metal oxides can
be efficiently controlled by external factors such as the temperature,
pressure, electric or magnetic field, they are regarded as promising materials
for various applications. From the viewpoint of electronic structure, these
phenomena are frequently related to the behavior of a small group of states
close to the Fermi level. The basic idea of this project is to construct a
low-energy model for the states near the Fermi level on the basis of
first-principles density functional theory, and to study this model by modern
many-body techniques. After a brief review of the method, the abilities of this
approach will be illustrated on a number of examples, including multiferroic
manganites and spin-orbital-lattice coupled phenomena in RVO3 (R being the
three-valent element).
