GHz units are normally used in the microwave region. For this region
it is also advised to use the VVW Flag
or Van Vleck Weisskopf lineshape in the *SHP
Internally the RFM always works in cm-1,
so spectral ranges defined in
GHz in the *SPC section
are converted to cm-1 using the factor
1E7/VLIGHT (approximately 1/30),
where VLIGHT, the speed of light, is defined in phycon.inc
(phycon_dat.inc in RFM v5).
Conversely, the spectral axis defined in header record#3 of the
output spectral files,
is converted back to GHz before being
written to the file.
may be expressed in either cm-1
or GHz. If incompatible with the GHZ Flag,
the appropriate conversion is made
and a warning message sent to the rfm.runlog file
(rfm.log for RFM v5.0)
.tab input/output files may be specified
on GHz or cm-1 axes, the RFM handles the conversion automatically.
All other spectral input data, e.g., in the
are always assumed to be in cm-1.