Programs in Physics & Physical Chemistry
|[Licence| Download | New Version Template] aesk_v1_0.tar.gz(1845 Kbytes)|
|Manuscript Title: OptaDOS: A Tool for Obtaining Density of States, Core-level and Optical Spectra from Electronic Structure Codes|
|Authors: Andrew J. Morris, Rebecca J. Nicholls, Chris J. Pickard, Jonathan R. Yates|
|Program title: OptaDOS|
|Catalogue identifier: AESK_v1_0|
Distribution format: tar.gz
|Journal reference: Comput. Phys. Commun. 185(2014)1477|
|Programming language: Fortran 95.|
|Computer: Any architecture with a Fortran 95 compiler.|
|Operating system: Linux, Mac OS X.|
|Has the code been vectorised or parallelized?: Yes, using MPI|
|RAM: 10 Mb|
|Word size: 32 or 64|
|Keywords: Electronic structure, Density-functional theory, Density of States, EELS, Optical spectra.|
|PACS: 31.15.E-, 79.20.Uv.|
|Classification: 7.2, 7.3.|
External routines: MPI to run in parallel, CASTEP
Nature of problem:
Many properties of materials can be described using integration over the Brillouin zone such as core-level and low-loss EELS and optical spectra. This integration is performed computationally using a grid of k-points. The discrete energy eigenvalues must be interpolated into a continuous spectra. The most common method broadens the eigenvalues using a Gaussian function. Gaussian broadening suffers from slow convergence with number of k-points and a difficulty in resolving fine spectral features.
OptaDOS improves the underlying Brillouin zone integration beyond fixed-width Gaussian broadening by using band gradients to perform adaptive and linearly extrapolated broadening. This increases the resolution of the predicted spectra.
Simple and user-friendly input system. Along with the usual band energies, band gradients are used to generate the linear extrapolation and adaptive broadening schemes producing a superior output able to represent both dispersive and localised bands concurrently.
The input data to OptaDOS are single-particle eigenenergies and dipole transition coefficients. OptaDOS has an interface to obtain these from the CASTEP plane wave density-functional theory (DFT) code. The interfacing of OptaDOS with other electonic structure codes, which are also capable of generating such inputs, is currently being undertaken
A few seconds to ~10 minutes.
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