PGOPHER
Colin Western
(help-pgopher@bristol.ac.uk)
School of Chemistry, University of Bristol, UK
Notes on new version (5.2):
Major new
features include a complete calibration mode,
symbolic matrix elements and use of multiple CPU's. There are also a
lot of small
improvements and fixes, based on feedback from the first main release.
This includes the display and input of quantum numbers as normal
values, rather than as double the true values and the contents of the
line list window is saved in the .pgo file so it can be used in a self
contained way for simple fits. See
here
for a full list. There are notes on
Upgrading
from previous versions, which are particularly important for
asymmetric tops. The quantum number format change can also requires
small changes to line list files.
PGOPHER
is a general purpose program
for simulating and
fitting rotational spectra. It represents a distillation of several
programs written and used over the past decade or so within the
Bristol
laser group and elsewhere, and the current version 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. (Note that previous
Bristol
PGOPHER program
handled linear molecules only.)
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
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, with beta versions
available for Linux and Apple Mac. The program is released as open
source, and can be compiled with open source tools.
Graphical User Interface Features
- Simple enough to use for undergraduate practicals, but flexible
enough to use for multiple interacting states.
- Multiple simulations coloured by species, isotope, state or
transition type.
- Interactively changing spectrum range, temperature, linewidth,
display style.
- Displaying Fortrat diagrams and energy level plots
- Select transitions by lower
or upper state J, symmetry
or ΔJ.
- Right clicking on peaks to see assignment.
- Overlaying experimental spectra
from file(s) or the
clipboard (frequency, intensity format).
- Overlay pictures from pdf
files or other
- Alt+left mouse dragging experimental spectra to adjust offset
between simulation and overlay.
- Built in Calibration (I2,
Ne, Fe) for experimental spectra.
- Energy Level plots.
Calculation Features
- Linear molecules in Hund's
case (a) or (b). (Other cases can be
handled with some restrictions.)
- Symmetric top molecules
- Asymmetric top molecules
- Open and closed shell systems (symmetric tops are currently
closed shell only)
- Simulates microwave, infra-red and electronic absorption
and emission spectra.
- Multiphoton and Raman transitions,
with any
combination of transition moments including interfering transition
moments.
- Handling an arbitrary number of states and perturbations between
them.
- Fitting to line positions,
band contours or line intensities.
- Flexible input formats,
including HITRAN (http://www.hitran.com)
.par files and JPL
(http://spec.jpl.nasa.gov/)
.cat files.
- Many molecular parameter (.par) data files for Herb Pickett's
CALPGM spectroscopy program suite (http://spec.jpl.nasa.gov/)
can be imported as PGOPHER input files.
- Handling arbitrary combinations of isotopes and molecules with
spectra coloured for easy identification.
- Simulate effects of quantum number dependent predissociation on
line width and intensity.
- Hyperfine structure (not currently for symmetric tops).
- Symbolic matrix elements available for linear molecules and
asymmetric tops. (Right click on a state or constant and select Matrix Elements)
- For larger calculations, parallel
calculations can be done on systems with multiple CPU's.
Supported Platforms
- Windows 9x/2000/XP
- Linux (Tested under Fedora Core 3-6, Red Hat Enterprise
3&4, Suse 9.3)
- Apple Mac (Tested under 10.3)