NSYM 
Hyperfine
structure in a linear/symmetric rotor with a single quadrupolar nucleus

This is a simple
predictive program as found in the (now defunct) EXETER, UK rotational spectroscopy group of A.C.Legon. The changes made
concern only commenting and output.

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ASQ1P 
Prediction of
hyperfine structure in a rotor with a single quadrupolar nucleus

This
program calculates the nuclear quadrupole splitting structure for an
asymmetric top with a single quadrupolar nucleus. The calculation is
only first order but the program is tailored towards producing quick
diagnostic plots for confrontation with spectra.
ASQ1P
calculates frequency shifts, relative intensities, as well as
coefficients a and b of χ_{aa}
and χ_{bb}
in the expression:
ν _{hyperfine}
= ν _{hyperfinefree}
+ a χ_{aa}
+ b χ_{bb}
These
coefficients can then be used in an external least squares program to
fit χ_{aa}
and χ_{bb}_{}
from just the splittings, and/or to derive hyperfine free transition
frequencies.
The
recommended extension for data is .ASQ



ASQ1P.FOR 
The
listing 
ASQ1P.EXE 
Windows executable 


H2OHCLAR.ASQ 
Specimen
data set for the trimer (H_{2}O...HCl)...Ar.
Please note that, as implied by the
primes, the quantum numbers of the upper level should come first. If
the transition declared in this way is a Ptype transition (J'
< J'') then you will find that in the output the program
will change the arrow direction and the order of the labels. The arrow
direction will still be consistent with the implication in the input
that E(J') > E(J''). When in
doubt you can always check against Appendix I of the 3rd edition of
Gordy&Cook.

H2OHCLAR.RES 
Results file for the data above 



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Q2FIT 
Fitting of nuclear
quadrupole coupling in a rotor with up to 2 quadrupolar nuclei

The
program has an excellent pedigree since its predecessor was written in
Flygare's group (by W.G.Read). Q2FIT fits transitions assigned in the I,F
coupling scheme of the two nuclear spins with rotation, the calculation
is in full diagonalization and includes spinrotation and spinspin
terms. We have actually switched to SPFIT for such problems, but Q2FIT is sometimes useful for comparisons.
The
main limitation is that on the fitted offdiagonal quadrupolar tensor
components, since only either χ_{a}_{b}
or χ_{a}_{c} can be fitted. There is also no
factorisation.
The
recommended that extension for data files is .Q2S



Q2FIT.FOR 
The
listing 
Q2FIT.EXE 
Windows executable 


VHCL.Q2S 
The data set for the
Hbonded complex vinyl fluoride...HCl (only the Cl nucleus), for which
a particularly strong quadrupole mediated perturbation has been fitted,
J.Chem.Phys. 93,3054(1990) 
VHCL.RES 
Results for the above 
ARCLCN.Q2S 
The data set for the
vdWaals complex Ar...ClCN (Cl and N nuclei) set up from results in J.Chem.Phys.
75,631(1981) and reproducing the constants therein 
ARCLCN.RES 
Results for the above 



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QDIAG 
Diagonalization of the
inertial quadrupole tensor (with errors)

QPRINC 
Rotation of the
nuclear quadrupole tensor

QDIAG
diagonalizes the inertial quadrupole tensor and the features are as
follows:
 calculation of principal tensor components
and their errors
 calculation of direction cosines and their
errors
 calculation of quadrupolar rotation angles
and their errors
 constants fitted by SPFIT, i.e. (3/2)χ_{aa}_{}, (χ_{bb}χ_{cc}_{})/4
etc. can be plugged in directly
 input is always taken from the top of the
file QDIAG.INP
 there is no explicit output to disk so for
hardcopy use a pipeline such as QDIAG>qdiag.out
QPRINC
serves to predict the inertial tensor from guessed principal quadrupole
components and the angular difference between the inertial and
principal quadrupole tensors. As for QDIAG the data is taken automatically from the top of the file QPRINC.INP, and if
you want hardcopy use the pipeline QPRINC>qprinc.out.



QDIAG.FOR 
The
listing 
QDIAG.EXE 
Windows executable 


QDIAG.INP 
Several examples of
literature tensors for QDIAG. Only the top declaration is read by the program. 
QDIAG.OUT 
Results for the data
set as above obtained with the pipeline command QDIAG>qdiag.out 
QDIAGA.OUT 
Results for diagonal quadrupole components
specified as (3/2)χ_{aa}_{}
and (χ_{bb}χ_{cc}_{})/4
obtained by bringing one of the lower declarations in QDIAG.INP to the top. 

QPRINC.FOR 
The listing 
QPRINC.EXE 
Windows executable 


QPRINC.INP 
Specimen data,
rotation is only in the ab=xz plane 
QPRINC.OUT 
Results for the above 



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