A quasi-Newton Method is used to simultaneously relax the internal coordinates and lattice parameters of crystals under pressure. The symmetry of the crystal structure is preserved during theâ€¦ (More)

We have determined the hydrogen-bond geometry in liquid water from 0 to 80 degrees C by combining measurements of the proton magnetic shielding tensor with ab initio density functional calculations.â€¦ (More)

We present a detailed ab initio study of the electronic and structural properties of the recently discovered R8 phase of silicon. Within the framework of density-functional theory in theâ€¦ (More)

We report the results of ab initio density functional theory calculations of the NMR chemical shift of liquid water and hexagonal ice. Depending on the structural model used, the calculated isotropicâ€¦ (More)

Electronic structure calculations based on Density Functional Theory (DFT) are an important branch of computational physics. We present a convergence analysis for the conjugate-gradient minimizationâ€¦ (More)