EN
The electronic structure of the tetragonal RMn_{2}Ge_{2} (R = Ca, Y, La, Ba) antiferromagnets is presented using the self-consistent Korringa-Kohn-Rostoker method. According to the neutron refinements, two types of collinear antiferromagnetic structure are taken into account: AF_{1} for YMn_{2}Ge_{2} and AF_{2} for the other compounds. The calculated magnetic moments on Mn: 2.17μ_{B} (YMn_{2}Ge_{2}), 2.84 μ_{B} (CaMn_{2}Ge_{2}), 2.95 μ_{B} (LaMn_{2}Ge_{2}), and 3.47 μ_{B} (BaMn_{2}Ge_{2}) remain in good agreement with the neutron data (in μ_{B}) 2.20, 2.67, 3.05, and 3.66, respectively. As seen on antiferromagnetic density of states, all systems are metallic, however BaMn_{2}Ge_{2} is found near semimetallic limit. The total energy Korringa-Kohn-Rostoker computations on CaMn_{2}Ge_{2}, performed in both antiferromagnetic phases, result in preferring of the AF _{2} structure.