Notes on common error messages
No error message, but no simulated spectrum either
- Try the
button
- your spectrum may simply
not be in the current plot range.
- The transition moment between the states of
interest may not be correct; check that one is present, and that the
component or axis is
set to give a transition between the states involved.
No error message, but the simulated spectrum or exported plot does
not look as expected
If the plotted spectrum shows with no
net width to lines, either
because you have not chosen to set one with "Gau" or "Lor", or because they are
rather smaller than the effective plot resolution, then the resulting
plot can easily be misleading. This is because of issues with closely
spaced transitions - do they combine as one strong line or several weak
ones? A physically meaningful plot is only guaranteed if the resolution
of the plot, equal to (Fmax - Fmin)/nDF, is significantly less (by
a factor of 3 or more) than the linewidth used for the simulation.
Problem loading a .pgo or .ovr file
The PGOPHER native format
.pgo and .ovr files must have the right extension to load correctly;
when downloading from a web page or from an email the extension can
sometimes be changed to .xml, or .xml is added to the filename. To fix
this, simply rename the file to have the correct extension. (Versions
of PGOPHER after 6.0.163
will load files that have been renamed in this way automatically.) If
this is not the problem, both types of files are xml text files, and
can be edited with most text editors.
"Overflow in Boltzmann for xxxxx: E=-nnnnnnn"
This results from a large negative
energy causing the Boltzmann
expression exp(-
E/
kT) to overflow. See the discussion
of
J range and Partition Functions for a
discussion of the causes of this problem and possible solutions.
Progress dialog stuck on Partition Function sum
This can indicate too many levels included in the partition function,
possibly because the parameters correspond to levels much too close
together. See the discussion
of
J range and Partition Functions for a
discussion of the causes of this problem and possible solutions.
"Odd and even numbers of electrons in xxxx"
Did you remember to set the right
spin for all states? This results if,
for example you have the changed the ground state to doublet and left
the excited state as singlet (the default).
"Mix of integral and half integral quantum numbers"
The error message means that you have
asked PGOPHER to
calculate an
impossible level, such as a J
= 1/2 level for a triplet state. This error message is likely to arise
on upgrade to version 5.2, if you are using an observation file
prepared for version 5.1. You may need to add the following directive
to the start of the observations file:
QuantumNumberFormat 2J
See the upgrading
section for more on this.
"Singular Matrix"
When least squares fitting, this
normally means that you have floated a
parameter (or some combination of parameters) that is not determined
from the supplied experimental data. For example, you may well see this
if you attempt to float both the upper and lower state origin for a
transition, as only the difference is determined. To fix this, float
fewer (or at least different) parameters.
"Inconsistent Statistical Weights"
This error occurs when two states
with the same
J and symmetry
but with different statistical weights are included in the same
Hamiltonian matrix.
- For linear molecules, this will currently occur
if gerade and ungerade states in linear molecules
are included in the same manifold, as PGOPHER does not currently
implement this. Such states can't mix anyway, so move them to a
separate
manifolds, at a minimum one for g
states and one for u states.
- For asymmetric tops this indicates that the eeWt, eoWt ... settings are
inconsistent with the choice of symmetries. (Setting all four to the
same value will stop the error message, though this is (probably) not
right if you have equivalent nuclei.)
PGOPHER