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Zero-point energy restrictions

D surface. The second, and more important, is the inability of the classical simulations to enforce zero-point energy restrictions throughout the... [Pg.222]

The fact that there is no zero-point energy may seem to conflict with the uncertainty principle. However, when the rotor stops, it could happen anywhere on the circle and that accounts for the uncertainty. The expression L2 = 2El = h2k2 shows that the angular momentum, L is restricted to integral multiples of h. [Pg.270]

An initial equilibrium structure is obtained at the Hartree-Fock (HF) level with the 6-31G(d) basis [47]. Spin-restricted (RHF) theory is used for singlet states and spin-unrestricted Hartree-Fock theory (UHF) for others. The HF/6-31G(d) equilibrium structure is used to calculate harmonic frequencies, which are then scaled by a factor of 0.8929 to take account of known deficiencies at this level [48], These frequencies are used to evaluate the zero-point energy Ezpe and thermal effects. [Pg.70]

From an entropic viewpoint, imposition of even a fairly mild restriction on the vibrational amplitude reduces the entropy associated with that vibration essentially to zero, and little significant additional loss is possible on further restriction. Although a bond with a i/ of 1000 cm has a substantial vibrational amplitude owing to its zero point energy, it has only 0.1 eu of entropy because only a small number of quantum states are effectively occupied. Further restriction on the magnitude of this vibrational amplitude will further reduce this small residual entropy but will not significantly increase the much larger difference in entropy between these restricted states and that of a free rotation. [Pg.20]

QCISD with the added contribution of triple (T) substitutions relativistic compact effective potentials restricted Hartree-Fock zero-point energy... [Pg.2]

With respect to lifetimes of the light-induced HS states of the order of minutes to days, LIESST is restricted to iron(II) spin-crossover compounds with a small zero-point energy difference, between the HS and the LS state. From the point of view of the double intersystem crossing step, LIESST is more general than that. It can also be observed for LS systems provided sufficiently fast excitation and detection methods are being used for monitoring the (in this case) much faster decay of the light-induced HS state (see below). [Pg.430]

The harmonic oscillator has finite zero-point energy. (The evidence for this in Fig. 3-2a is the observation that the line for the lowest (n = 0) energy level lies above the lowest point of the parabola, where V = 0.) This is expected since the change from square well to parabolic well does not remove the restrictions on particle position it merely changes them. [Pg.74]

The s-type solution has zero energy. One can imagine that the reduced mass is motionless on the surface of the sphere and has equal probability for being found anywhere. This transforms back to a picture where the diatomic molecule is not rotating and where there is no preferred orientation. Since E = 0 when 7 = 0, we conclude that there is no zero-point energy for free rotation. (However, if rotation is restricted so that some orientations become preferred, the zero-point energy becomes finite.)... [Pg.118]

There is no restriction on the values of the parameter c except that it must be real. The energy eigenvalue E, which is equal to the kinetic energy, can take on any real non-negative value. The energy is not quantized and there is no zero-point energy. [Pg.671]

Let us review the calculation of the number of electrons in successive Brillouin zones. The calculation has as its starting point a distribution of free electrons. In a volume V to which the electrons are restricted the most stable pair of electrons occupies the lowest energy levels, with nearly zero kinetic energy, and correspondingly long wave-lengths. As the number of electrons... [Pg.366]


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See also in sourсe #XX -- [ Pg.223 ]




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