Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Orbital balancing

Equation (175) cannot be easily solved because the matrix Xs)pg has a lot of vanishing eigenvalues. Moreover if the auxiliary basis set in not properly balanced with the orbital-basis set, spurious oscillation in the EXX potential appears.HeBelman et proposed to construct an balanced orbital basis set from a given auxiliary basis set. [Pg.149]

The three signals are fed into an oscilloscope as vertical-, horizontal-, and external-intensity marker input. The keyphazor appears as a bright spot on the screen. In cases where the orbit obtained is completely circular, the maximum amplitude of vibration occurs in the direction of the keyphazor. To estimate the magnitude of the correction mass, a trial-and-error process is initiated. With the rotor perfectly balanced, the orbit finally shrinks to a... [Pg.591]

Jackson, C., Using the Orbit to Balance, Mechanical Engineering, pp. 28-32, February 1971. [Pg.603]

Theoretically, for a particle of a given size that moves in the highly rotating fluid flow in a cyclone, a particular radial orbit position may be found in every horizontal plane of the cyclone where the outward centrifugal force is just balanced by the drag exerted on the particle by the radial inward fluid flow. If Stokes s law (13.16) is assumed, then the position of the equilibrium orbit on each horizontal plane of the cyclone may be obtained and is given by... [Pg.1205]

Hudson has noted that any explanation of the a effect must account both for the enhanced nucleophilicity and the lack of effect on the Ka of the nucleophile he attributes the a effect to a balance (which is different for nucleophile-carbon and nucleophile-proton interactions) between an orbital splitting eontribution and an electrostatie bond polarity factor. [Pg.357]

A more balanced description requires MCSCF based methods where the orbitals are optimized for each particular state, or optimized for a suitable average of the desired states (state averaged MCSCF). It should be noted that such excited state MCSCF solutions correspond to saddle points in the parameter space for the wave function, and second-order optimization techniques are therefore almost mandatory. In order to obtain accurate excitation energies it is normally necessarily to also include dynamical Correlation, for example by using the CASPT2 method. [Pg.147]

So the question should never be (nor has it ever been) one of choosing between all catalytic chemists studying ortho-para hydrogen conversion, molecular orbitals and the like, or all catalytic chemists studying fuel synthesis and exhaust catalysts a healthy society is a judiciously balanced society, and the concern for relevance is one for a shift toward greater dedication in the direction of the most vital needs for the survival and health of the kinetic system of human society. [Pg.441]

The goodness of the PP representation can be checked by comparing the all-electron and PP orbital energies and relative stability of atomic states. The comparison is shown in Table 4, and is seen to be very satisfying. For a balanced treatment, also the carbon and oxygen atoms were treated by a PP, as described in previous work5.3d functions were not introduced in the sulphur basis set, mainly because they were not deemed necessary for the illustrative purposes of this chapter. Also, the derivation of a PP representation for polarization functions is not a straightforward matter. The next section is devoted to the discussion of this point. [Pg.17]

The Brueckner-reference method discussed in Section 5.2 and the cc-pvqz basis set without g functions were applied to the vertical ionization energies of ozone [27]. Errors in the results of Table IV lie between 0.07 and 0.17 eV pole strengths (P) displayed beside the ionization energies are approximately equal to 0.9. Examination of cluster amplitudes amd elements of U vectors for each ionization energy reveals the reasons for the success of the present calculations. The cluster operator amplitude for the double excitation to 2bj from la is approximately 0.19. For each final state, the most important operator pertains to an occupied spin-orbital in the reference determinant, but there are significant coefficients for 2h-p operators. For the A2 case, a balanced description of ground state correlation requires inclusion of a 2p-h operator as well. The 2bi orbital s creation or annihilation operator is present in each of the 2h-p and 2p-h operators listed in Table IV. Pole strengths are approximately equal to the square of the principal h operator coefiScient and contributions by other h operators are relatively small. [Pg.48]


See other pages where Orbital balancing is mentioned: [Pg.21]    [Pg.21]    [Pg.21]    [Pg.21]    [Pg.2226]    [Pg.377]    [Pg.100]    [Pg.232]    [Pg.101]    [Pg.101]    [Pg.480]    [Pg.193]    [Pg.590]    [Pg.591]    [Pg.592]    [Pg.30]    [Pg.452]    [Pg.1159]    [Pg.1232]    [Pg.122]    [Pg.161]    [Pg.682]    [Pg.274]    [Pg.232]    [Pg.114]    [Pg.3]    [Pg.177]    [Pg.444]    [Pg.245]    [Pg.45]    [Pg.195]    [Pg.274]    [Pg.529]    [Pg.535]    [Pg.1453]    [Pg.9]    [Pg.65]    [Pg.142]    [Pg.383]   


SEARCH



© 2024 chempedia.info