PGOPHER, a program for simulating rotational structure

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2 Apr 2013: Apologies for the website outage due to a hardware failure. Everything including the interactive samples should now be working, but note that a further short outage may be required soon to allow for a move to a new server

15 Mar 2013: Incorrect values for the Einstein A coefficient can be displayed if the plot units are different from the calculation units. This is fixed in versions after 7.1.325; for older versions just make sure the plot units and calculation units are the same when A is required.

28 Jul 2011: Selected transitions are omitted for simulations of the unusual symmetric top point groups C3h...C6h (involving states with E symmetry) and S4...S12 (for non totally symmetric states). An initial fix has been made in version 7.1.217 and above, available under development versions.

7 Feb 2011: An issue with simulating spectra with equivalent nuclei has been discovered. It arises if either:

The issues have been fixed in version 7.1.145 and above, currently available under development versions.

13 September 2010 - Version 7.1: Bug fix release - In the vibrational only mode, linear molecule Franck-Condon factor calculations for states with non zero vibronic angular momentum had incorrect intensities, as the degeneracies were not properly accounted for. A few other minor issues have also been fixed.

15 June 2010: New Full Release (7.0): Apart from many minor improvements and bug fixes, several features have been added at the request of users:

See here for a detailed list of changes, including notes on upgrading from previous versions.

PGOPHER is a general purpose program for simulating and fitting rotational, vibrational and electronic spectra. It represents a distillation of several programs written and used over the past decade or so within the Bristol laser group and elsewhere, but is a re-write from scratch to produce a general purpose and flexible program. PGOPHER will handle linear molecules and symmetric and asymmetric tops, including effects due to unpaired electrons and nuclear spin, with a separate mode for vibrational structure. The program can handle many sorts of transitions, including Raman, multiphoton and forbidden transitions. It can simulate multiple species and states simultaneously, including special effects such as perturbations and state dependent predissociation. Fitting can be to line positions, intensities  or band contours.

PGOPHER is designed to be easy to use; it uses a standard graphical user interface and the program is currently in use for undergraduate practicals and workshops as well as research work. It has features to make comparison with, and fitting to, spectra from various sources easy. In addition to overlaying numerical spectra it is also possible to overlay pictures from pdf files and even plate spectra to assist in checking that published constants are being used correctly.

The program is freely downloadable from this web site for Microsoft Windows and Linux, with a beta version available for the Apple Mac. The program is released as open source, and can be compiled with open source tools. For support please contact help-pgopher@bristol.ac.uk

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