Multi structures

K. Niu, Analytical Model for Super-Compression of Multi-Structured Pellet , Rept No IPPJ-230, Nagoya Univ (Jap) (1975)... 

This is, of course, the approach used by all of the early VB workers. In more recent times, after computing machinery allowed ab initio treatments, this is the sort of wave function proposed by Balint-Kurti and Karplus[34], which they called a multi structure approach. The present author and his students have proposed the multiconfiguration valence bond (MCVB) approach, which differs from the Balint-Kurti-Karplus wave function principally in the way the , are chosen. 

In the development of the TURTLE program [3], we started by considering a multi-structure Valence Bond wavefunction and added the capability to optimise the orbitals. We tried to avoid putting restrictions on the way the wavefunction is built and to allow great flexibility in the choice of orbitals. For... 

The leading principles of the method are straightforward. To calculate a given electronic state, all the Lewis structures that are relevant for the qualitative VB description of this state are generated, and the covalent forms are distinguished from the ionic ones. Each of these Lewis structures is represented by a single VB function which has its specific set of orbitals. The orbitals and the coefficients of the VB structures are optimized simultaneously, to minimize the energy of the final multi-structure state. 

I. Yuranov, A. Renken, L. Kiwi-Minsker, Zeolite/sintered metal fibers composites as effective multi-structured catalysts, Appl. Catal. 281 (2005) 55. 

Zhang, J.T., The multi-structural feature of the multidrug resistance gene product P-glycoprotein implications for its mechanism of action (hypothesis), Mol Membr Biol 18 (2001) 145-152. 

Of course, since the VB model is multi-structure (that is, equivalently, multideterminant) by definition, correlation energy is not computed separately and, if an explicit evaluation of the correlation energy is required, a HF calculation using the same orbital basis must be done to provide a baseline. 

To take the correlation contribution to water dimer interaction energy into account, a very compact multi-structure VB - non-orthogonal Cl - calculation is carried out. With this aim, a method to obtain virtual orbitals corresponding to the SCF-MI wavefunction which furnishes an energetic contribution of the same accuracy as very extended Cl calculations, was developed. In order to avoid that BSSE switches on, both the occupied - f and virtual Of. - Of. SCF-MI orbitals are constrained to the restrictions... 

The virtual orbitals obtained by means of the perturbation theory approximation are then employed to construct a full set of all the singly- and doubly-excited configurations which provide the final VB-like wavefianction Eq. (11). Finally, the multi structure VB (non-orthogonal Cl) problem is set up and solved vaiiationally according to standard VB techniques, see Raimondi et al (1977) and Cooper et al, (1987). 

Multi-structure interpolation methods chain, locally updated planes, self-penalty walk, conjugate peak refinement and nudged elastic band... 

There may be several TS s (and therefore at least one minimum) between the two selected end-points. Some algorithms may find one of these, and the two connecting minima can then be found by tracing the IRC path, or all the TS s and intermediate minima may be located. Multi-structure methods (e.g. NEB) are examples of the latter behaviour. 

The multi-structure methods are quite tolerant towards the presence of many soft degrees of freedom, which often causes problems with the local optimization methods described in Sections 12.4.5-12.4.7. Multi-structure methods such as NEB are therefore well suited for large systems such as extended (periodic) systems. 

Sun, B., Hu, D., and Gu, B. (2009) Transverse impact damage and energy absorption of 3-D multi-structured knitted composite. Composites PartB Engineering, 40, 572-583. 

It remains the problem of taking into account the resonance effect when eompu-ting properties of systems which are represented by a superposition of hybrids of resonance. This can be aeconq>lished with the Generalized Multi-structural (GMS) wavefimetion. Only a brief description will be presented since the theory... 

Huang et al. produced nanostmctured ZnO using microwave hydrothermal synthesis. In a typical synthesis process, Zn(N03>2 was dissolved in deionized water. NaOH was added to form a colloid solution. The solution was transferred into an autoclave and treated at 140 °C for 20 min, under temperature-conbolled mode or at 3.0 MPa for 20 min under pressure-controlled mode in a MDS-6 microwave hydrothermal system. ZnO nanostrucured forms such as rods, wires, thrusters, dandelions and spindles were formed using different temperature and pressure conditions. Figure 6.7 suggests a mechanism of this multi-structure formation. 

It is becoming obvious that because of the previously unsuspected problems of multi-structure complexes, cooperativlty, conformational changes, and allotopy, the problem of drug-receptor complexes is very much more Involved than the classical concept of a "lock—and-key" interaction. 

Using the new method it can be thought that ACF I is consisted of multi-structural elements, and the structural elements are same in apo-ACF I in guanidine hydrochloride. The stability of structural element can be described by parameters [D]i/2 (1.22M) and m (-4.06 kcal/M/mole), i.e. AG0(H2O) is 4.96 kcal/mole. After binding Ca2+ the structural elements are changed. At least three-kind structural elements appear in holo-ACF I. Their stability is 4.22 kcal/mole, 7.07 kcal/mole, and 5.95 kcal/mole, for structural element 1, 2, and 3, respectively. 

Multi-Structural Wave Function. The He/ Molecule as an Example. 

CACTVS tools Extensive set of tools, multi-structure 2D display browser and spectral viewer are especially useful 30 formats, extensible by dynamic I/O modules... 

---