|Molecule Types Linear Molecules||<Prev Next>|
Note that only nuclei not explicitly simulated with nucleus
objects should be included in calculating the SymWt and AsymWt statistical weights. If all
equivalent nuclei have been explicitly included, then the
statistical weights should be calculated as if there were an
additional pair of equivalent spin zero nuclei, which will mean
AsymWt must be set to zero. A simple
check for correct operation is to compare the rotational
structure with and without the nuclei explicitly included, with
the weights calculated in the latter case including all nuclei.
If the linewidth is set somewhat larger than the width of the
hyperfine structure the spectra should appear identical.
For interactions between nuclei, see the Nuclear Spin - Nuclear Spin Coupling.
|AsNext||Set to indicate that this nucleus is equivalent to the
following nucleus. This is required for molecules with a
centre of symmetry, where nuclei not on the centre of
symmetry must occur as equivalent pairs. In these
circumstances all parameters are taken from the second of
the two nuclei, and the modified coupling scheme:
I12 = I1 + I2; F = J + I12is used.
This setting can also be used for molecules without a centre of symmetry, in which case the alternate coupling scheme is used but the nuclei are not forced, or even required, to be identical.
|MaxDJ||Maximum ΔJ to include to
consider in evaluating matrix elements for this nucleus.
Default is negative, which includes all possible matrix
elements, but setting this to zero (or possibly 1) can give
significantly faster calculations but may be less accurate,
particularly for low J.
|a||Nuclear spin - orbit interaction, I.L.|
|b||Nuclear spin - electron spin I.S. Note that b = bF - c/3.|
|c||Nuclear spin - electron spin dipole dipole interaction diagonal in Lambda.|
|d||Nuclear spin - electron spin dipole dipole interaction off diagonal in Lambda by 2.|
|eQq0||Nuclear quadrupole coupling constant diagonal in Lambda.|
|eQq2||Nuclear quadrupole coupling constant off diagonal in Lambda by 2.|
|cI||Nuclear spin rotation, I.J. Note that I.N
= I.(J-S) is sometimes used, which is
equivalent to subtracting cI from b.
|cIp||cI' = Nuclear spin rotation, I.J
off diagonal in Lambda by 2. Note that the quivalent
operator involving N is equivalent to subtracting
cIp from d.
|aJ||Centrifugal distortion of nuclear spin - orbit interaction (I.L). (Outline implementation - a more exact implementation can be obtained with a perturbation with Op = bF and Npower = 2)|
|bJ||Centrifugal distortion of nuclear spin - electron spin
(I.S). (Outline implementation - a more exact implementation
can be obtained with a perturbation with Op = aL and Npower
|cJ||Centrifugal distortion of nuclear spin - electron spin dipole dipole interaction diagonal in Lambda. (Outline implementation)|
|dJ||Centrifugal distortion of nuclear spin - electron spin
dipole dipole interaction off diagonal in Lambda by 2. Note
that the full implementation was added in 10.1.151, and the
results from earlier versions will only be approximately
|eQq0J||Centrifugal distortion of nuclear quadrupole coupling constant diagonal in Lambda. (Outline implementation)|
|eQq2J||Centrifugal distortion of nuclear quadrupole coupling constant off diagonal in Lambda by 2. (Outline implementation)|