Ab initio studies on phase behavior of barium titanate

Uludogan, M
Cagin, T
Goddard, WA
Using DFT methods we have studied structure, equation of state, and phase behavior of BaTiO3. We have identified the pressure induced phase transformations from the rhombohedral to orthorhombic structure at ca. 5 GPa and from tetragonal phase to cubic phase at ca. 7.5 GPa.
Symposium on Perovskite Materials held at the 2002 MRS Spring Meeting


Parallel solution of soil-structure interaction problems on pc clusters
Bahçecioğlu, Tunç; Çetin, Kemal Önder; Department of Civil Engineering (2011)
Numerical assessment of soil structure interaction problems require heavy computational efforts because of the dynamic and iterative (nonlinear) nature of the problems. Furthermore, modeling soil-structure interaction may require finer meshes in order to get reliable results. Latest computing technologies must be utilized to achieve results in reasonable run times. This study focuses on development and implantation of a parallel dynamic finite element analysis method for numerical solution of soil-structure i...
Ab initio potential energy and dipole moment surfaces of the F-(H2O) complex
Kamarchik, Eugene; Toffolı, Danıele; Christiansen, Ove; Bowman, Joel M. (Elsevier BV, 2014-02-05)
We present full-dimensional, ab initio potential energy and dipole moment surfaces for the F-(H2O) complex. The potential surface is a permutationally invariant fit to 16,114 coupled-cluster single double (triple)/aVTZ energies, while the dipole surface is a covariant fit to 11,395 CCSD(T)/aVTZ dipole moments. Vibrational self-consistent field/vibrational configuration interaction (VSCF/VCI) calculations of energies and the IR-spectrum are presented both for F-(H2O) and for the deuterated analog, F-(D2O). A...
Ab initio study of the one-monolayer Sb/Si(001) interface
Cakmak, M; Shaltaf, R; Srivastava, GP; Ellialtıoğlu, Süleyman Şinasi (Elsevier BV, 2003-06-10)
Ab initio calculations, based on norm-conserving pseudopotentials and density functional theory, have been performed to investigate the displacive Sb adsorption on the Si(0 0 1) surface with the (2 x 1) reconstruction. For the one-monolayer coverage of Sb, even though the formation of a pure Sb-Sb dimer is energetically more favorable than the interdiffusion of Sb into any of the second and third substrate layers, we found further that this interdiffusion will relieve the tensile stress along the dimer bond...
Error estimates for space-time discontinuous Galerkin formulation based on proper orthogonal decomposition
Akman, Tuğba (Informa UK Limited, 2017-01-01)
In this study, proper orthogonal decomposition (POD) method is applied to diffusion-convection-reaction equation, which is discretized using spacetime discontinuous Galerkin (dG) method. We provide estimates for POD truncation error in dG-energy norm, dG-elliptic projection, and spacetime projection. Using these new estimates, we analyze the error between the dG and the POD solution, and the error between the exact and the POD solution. Numerical results, which are consistent with theoretical convergence ra...
Linear-linear basis functions for MLFMA solutions of magnetic-field and combined-field integral equations
Ergül, Özgür Salih (2007-04-01)
We present the linear-linear (LL) basis functions to improve the accuracy of the magnetic-field integral equation (MFIE) and the combined-field integral equation (CFIE) for three-dimensional electromagnetic scattering problems involving closed conductors. We consider the solutions of relatively large scattering problems by employing the multilevel fast multipole algorithm. Accuracy problems of MFIE and CFIE arising from their implementations with the conventional Rao-Wilton-Glisson (RWG) basis functions can...
Citation Formats
M. Uludogan, T. Cagin, and W. Goddard, “Ab initio studies on phase behavior of barium titanate,” SAN FRANCISCO, CA, 2002, vol. 718, p. 341, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/66579.