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PROGRAM SUMMARY
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Title of program:
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ONYX Version 2.1
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Catalogue identifier:
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ADLU
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Ref. in CPC:
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128(2000)590
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Distribution format: ** tar gzip file
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Operating system: ** UNIX V3.2D-1 (Rev. 41)
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High speed store required:
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23MK words
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Number of bits in a word:
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32
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Number of lines in distributed program, including test data, etc:
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13192
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Programming language used: ** Fortran
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Computer: ** Digital Alpha 250

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Other versions of this program:
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Cat. Id. Title Ref. in CPC ADIJ ONYX 112(1998)23

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Nature of physical problem:
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Efficient calculation of either photonic dispersion relationships,
Green's functions or transmission and reflection coefficients for
photons in complex dielectric structures.

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Method of solution
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A discretisation of Maxwell's equations in both the space and time
domains which leads to finite difference equations connecting the
electric and magnetic fields at one time step to those at the next.
After using these equations to find the response in the time domain to a
particular initial set of fields, we perform a Fourier transform to
obtain the response in the frequency domain. From this we can easily
extract dispersion relationship information, or alternatively, by
setting the initial fields to be a delta function, we can obtain the
Green's function for the system under consideration. In addition, by
projecting onto a complete basis set of plane waves we can find the
transmission and reflection matrices for the scattering system.

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Restrictions on the complexity of the problem
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The complexity of the dielectric structure that the method can be
applied to is limited only by the computer time and memory available.
Both time and memory requirements scale linearly with the system size.
One restriction on the method is that the dielectric permittivity and
magnetic permeability must both be independent of frequency. This means
it cannot treat some problems, typically those involving metals.

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Typical running time
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Highly dependent on the system under consideration. For the test
transmission calculation given, 120 seconds on a Digital Alpha 250
workstation.

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Unusual features of the program
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Option to work with non-orthogonal co-ordinate systems.