Molecule type

There is no one best method for describing solvent effects. The choice of method is dependent on the size of the molecule, type of solvent effects being examined, and required accuracy of results. Many of the continuum solvation methods predict solvation energy more accurately for neutral molecules than for ions. The following is a list of preferred methods, with those resulting in the highest accuracy and the least amount of computational effort appearing first ... 

Previous investigations might influence the choice of a molecular mechanics method. If molecular mechanics calculations of a particular compound or molecule type already exist, choose the same force field so you can make comparisons easily. 

Tautomerism involving compounds included in a host molecule (type 6) has been studied, in some cases involving triazoles and pyrazoles [87CL2317 88CL1061 93JCS(CC)1139] [the last reference describes a case of proton transfer for pyrazole included in l,l-di(2,4-dimethylphenyl)but-2-yn-l-ol]. 

The molecule, type AX2, is linear, with a bond angle of 180°. 

In case of [M(edt)2] based salts, the size of the small anion is similar to the size of the CsMes ligand of the cation and only type I structural motives (D+ A D+ A-chains) were observed. For the intermediate size anionic complexes, [M(tdx)2], [M(mnt)2] and [Ni(a-tpdt)2], the most common structural motive obtained in salts based on those anions is also of type I. For the larger anionic complexes, [M(bdx)2] and [M(dmix)2], types III and IV chain arrangements were observed. In both cases anion molecules (type IV) or face-to-face pair of anions (type III) alternate with side-by-side pairs of cations. The complexes [M(mnt)2] and [M(dmix)2] (M = Ni, Pd and Pt) frequently present dimerization in the solid state [19], and they are the only anions where the chain arrangements present face-to-face pairs of anions (structural motives II and III). The variety of structural... 

This molecule (type AB2) does not obey the octet rule without modification. 

The Lewis formula for the molecule (type AB4) predicts 4 electron groups around the central Sn atom and a tetrahedral electronic geometry. Since there are no lone pairs on Sn, the molecular geometry is also tetrahedral (Section 8-7). 

The Lewis formula for the molecule (type AB2U) predicts 3 electron groups around the central N atom including 1 lone pair of electrons. The electronic geometry is trigonal planar and the molecular geometry is angular or bent (Table 8-3). 

This molecule (type AB2) has a linear electronic and molecular geometry. The Cd-I bonds are polar. Since the molecule is symmetric, the bond dipoles cancel to give a nonpolar molecule (Section 8-5). 

This molecule (type AB3U) has a tetrahedral electronic geometry and a pyramidal molecular geometry. Cl (EN = 3.0) is more electronegative than As (EN = 2.1). The polar As-Cl bond dipoles oppose the effect of the lone pair. The molecule is only slightly polar (Section 8-8). 

This molecule (type AB2U2) has a tetrahedral electronic geometry and an angular molecular geometry. Oxygen (EN = 3.5) is less electronegative than F (EN = 4.0). The O-F bond dipole opposes the effect of the two lone pairs of electrons and so, OF2 is polar (Section 8-9). 

The SCF solution, i.e. the condition that the segment densities and the segment potentials are consistent with each other, is found for a canonical ensemble. This means that the number of molecules of each molecule type is fixed. As explained above, membranes should be modelled in a (N, p, y, T), i.e. 

From the FIA—MS overview spectrum, speculation that there can be more than just one structurally defined molecule type behind an observable signal i.e. the presence of isobaric compounds, cannot be excluded whenever one signal defined by the m/z-ratio is examined in FIA-MS spectra. Consequently, the information obtained by FIA-MS is quite limited whenever we deal with complex mixtures of environmental pollutants rather than the analysis of pure products or formulations with a known range of ingredients. LC separation is inevitable when mixtures of isomeric compounds should be identified with MS-MS. Therefore, in FIA-MS-MS special attention has to be paid to avoid the generation of mixed product ion spectra from isomeric parent compounds. This would block identification by library search and may lead to misinterpretations of product ion spectra because of the fragmentation behaviour observed. 

Design acyclic compounds containing groups of C, H and O atoms (select all molecule types with C, H 0 atoms)... 

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