Using density functional theory, we investigate the structural, vibrational, and dielectric properties of titanium oxides and silicates, which have attracted considerable attention in the framework of the quest for alternative high-K materials. For the oxides,. three crystalline phases of titanium dioxide are considered. The first two are hypothetical; they are obtained by similarity with the cubic and tetragonal structure of zirconia ZrO2 or hafnia HfO2. The third is the rutile, a crystal that occurs naturally. For the silicates, we analyze a hypothetical TiSiO4 structure constructed by analogy with crystalline ZrSiO4 and HfSiO4 (zircon and hafnon). (C) 2004 Wiley Periodicals, Inc.