Competing orders and collective phenomena in transition metal compounds;

By the first principles plane-wave pseudopotential calculations based on the density functional theory,we studied the equations of states and structural properties of transition metal compounds OsB_2 and OsO_2 and the possible high pressure phase transitions of OsO_2.

Transition metal compounds is a main topic in condensed matter physics for their interesting and abnormal properties, such as high-T_c superconductivity, high thermoelectric efficiency, et al, which have attracted much attention of researching.

Dipole moments, polarizabilities and first hyperpolarizabilities of a series of transition metal complexes have been studied by employing various exchange-correlated potentials within the density functional theory (DFT).