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Symmetric states relativity theory

In summary, transition structures with dioxirane and dimethyldioxirane are unsymmet-rical at the MP2/6-31G level, but are symmetrical at the QCISD/6-31G and B3LYP/6-31G levels. The transition states for oxidation of ethylene by carbonyl oxides do not suffer from the same difficulties as those for dioxirane and peroxyforaiic acid. Even at the MP2/6-31G level, they are symmetrical (Figure 17). The barriers at the MP2 and MP4 levels are similar and solvent has relatively little effect. The calculated barriers agree well with experiment . In a similar fashion, the oxidation of ethylene by peroxyformic acid has been studied at the MP2/6-31G, MP4/6-31G, QCISD/6-31G and CCSD(T)/6-31G and B3LYP levels of theory. The MP2/6-31G level of theory calculations lead to an unsymmetrical transition structure for peracid epoxidation that, as noted above, is an artifact of the method. However, QCISD/6-31G and B3LYP/6-31G calculations both result in symmetrical transition structures with essentially equal C—O bonds. [Pg.37]

In summary, the model allows for two types of interactions between the mirror spaces, the weak kinematical perturbation and the adiabatic and sudden limits equivalent to Eq. (17) or Eqs. (29)-(34). The overwhelming rate of particles over antiparticles in the Universe is inferred in this picture once the particular particle state has been selected. The Minkowski metric of the special theory of relativity is represented here by a non-positive definite metric, Eq. (8), bringing about a quantum model with a complex symmetric ansatz. Although the latter permits general symmetry violations, it is nevertheless surprising that fundamental transformations between complex symmetric representations and canonical forms come out unitary. [Pg.131]

There has been a growing recognition of the significance of the symmetrization postulate for nuclear spin relaxation of quantum rotors in the solid state. However, even the conventional theories of the latter phenomenon, based on the classical jump model, are specialized to such an extent that for a proper presentation of the problem a separate review should be provided. Therefore, only a brief reference will be made here to a recent paper where a consistently quantum description of the relaxation behaviour of weakly hindered CD3 rotors is reported.The relevance of the latter work to the content of the present review stems from the fact that the relaxation processes are described therein in terms of essentially the same quantum coherences as those entering the DQR theory of NMR line shapes addressed in Section 4.1. This points to a relative generality of the DQR theory. [Pg.37]

The self-consistent field theory phase diagram is also likely to be inaccurate at low relative molecular mass, because, like any mean-field theory, it neglects fluctuations. The effect of fluctuations is to stabilise the disordered phase somewhat (Fredrickson and Helfand 1987) in addition the seeond-order transition predicted for the symmetrical diblock is replaced by a first-order transition and, for asymmetrical diblocks, there are first-order transitions directly from the disordered into the hexagonal and lamellar phases. In addition it seems likely that fluctuations tend to stabilise high symmetry states such as the gyroid (Bates et al. 1994). [Pg.286]

Here the probabilities in each matrix are normalised to make the highest probability unity in each. In the more general theory, the factor x is re-expressed in terms of the rotational constraints on individual bonds, and one typically needs five such variables for an acceptable description of an un-symmetrical vinyl polymer in which each bond has three rotational states. In the above case it may simply be defined as the relative probability of the gg state in the racemic dyad. [Pg.151]


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Relativity, theory

State symmetric

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