Computer Physics Communications Program LibraryPrograms in Physics & Physical Chemistry |

[Licence| Download | New Version Template] aesk_v1_0.tar.gz(1845 Kbytes) | ||
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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_0Distribution 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. | ||

Solution method: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. | ||

Unusual features: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. | ||

Additional comments: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 | ||

Running time:A few seconds to ~10 minutes. |

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