Geometric, electronic and elastic properties of dental silver amalgam γ-(Ag3Sn), γ1-(Ag2Hg3), γ2-(Sn8Hg) phases, comparison of experiment and theory

Geometric, electronic and elastic properties of three intermetallic systems, including starting alloy (Ag3Sn) and two reaction product phases (Ag2Hg3 and Sn8Hg), are characterized by state-of-the-art density functional theory (DFT) experiments. The traditional mean-field approach failed for Sn8Hg (γ2-phase) due to inaccurate description of site occupancy, remedied through the use of supercells. Results were in quantitative agreement with experiment for all phases, within 3.2% and 2.7% for unit cell parameters and Young modulus (of elasticity), respectively. An efficient procedure is presented which may lead to the rational design of novel filling materials for such service, prior to physical trials being initiated.