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PGOPHER

Colin Western (help-pgopher@bristol.ac.uk)
School of Chemistry, University of Bristol, UK

Version 8.0 (2 December 2013): A significant new release of PGOPHER, with the major new feature being the addition of the calculations involved in a Force Field Analysis to PGOPHER. This allows vibrational frequencies and many other related quantities including Franck-Condon factors and centrifugal distortion distortion constants to be calculated from a force field expressed in terms of bond bending and stretching coordinates or symmetry coordinates. Fitting the force field to any reasonable combination of observations is also possible, and this has been set up so that scaling or otherwise adapting ab initio force fields is straightforward. Other significant new features include:
See the release notes for a detailed list of changes, including notes on upgrading from previous versions.

Version 7.1 (13 September 2010):
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.

New in version 7.0 (15 June 2010): Apart from many minor improvements and bug fixes, several features have been added at the request of users:
New in the previous version (6.0):

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 a supporting web site at Bristol (http://pgopher.chm.bris.ac.uk), for Microsoft Windows, Apple Mac and Linux, with a beta version available for the . The data files are the same, regardless of the platform. The program is released as open source, and can be compiled with open source tools.

Graphical User Interface Features

Calculation Features

Supported Platforms

System Requirements

Most calculations will run on any reasonably modern machine; larger calculations involving multiple states can benefit from more memory or processors.