Atomic number, of atoms

Number of atoms number of atoms number of atoms... 

Atoms of an element have the same atomic number, which is different from the atomic number of atoms of any other element. 

Electronic structure calculations are generally concerned with solving the electronic ground state of a certain molecular ensemble based on hrst-principles quantum mechanics. The techniques are called ab initio if they require only the atomic numbers of atoms involved in the ensemble, and no adjustable parameters taken from experiment or other calculations. A good introduction into the various ab initio and other quantum-chemical methods is given in Jensen s book [4]. 

According to conventional theory, the equation Rexp = Rconv should also be valid for ECS. However, the cross section for electron scattering from hydrogen, carbon and oxygen is simply the Rutherford cross section ax oc Z (Zx atomic number of atom X). Calculations of the cross section based on the electronic structure show that screening effects are not important under these conditions [Vos 2002 (a) Chatzidimitriou-Dreismann 2003 (a)]. The results reveal that, as in the case of NCS, the measured ratio ReXp of the hydrogen peak and the joint oxygen / carbon peak is considerably decreased Rexp < Rconv-... 

Priority depends on the atomic number of atoms directly attached to the chiral carbon atom. If two or more directly attached atoms are identical, one proceeds along the groups until differences are found. In double and triple bonds the groups are considered to be duplicated or triplicated. 

The relative areas of peaks in the radial distribution curve can be estimated by Eq. 10.5, in which Z, and Zj are the atomic numbers of atoms i and j, and n,y is the number of times the distanee occius in the molecule. 

The sp carbon on the right is bonded to a Cl and to a C Cl has the greater atomic number, so Cl has the higher priority. (Notice that you use the atomic number of C, not the mass of the CH3 group, because the priorities are based on the atomic numbers of atoms, not on the masses of groups.)... 

If the sequence a, b, c of priorities of the groups is clockwise, the face toward the reader is re (rectus), if counterclockwise, si (sinister). If necessary, phantom atoms attached to C and O must be added to assign priorities on the basis of the atomic numbers of atoms surrounding the carbon of the carbonyl function. 

Consider now transfer at the interface. The rate at which the ad-atoms one interatomic distance a away are attached to the crystallite is equal to the circumferential area (a27rr sin 0) times the rate at which these atoms ( number of atoms/ area) jump over the energy barrier A d, i.e., [2irr a sin 0]n where the jump frequency is given by ... 

The charge attributed to an atom A within a molecule, defined as = Za — where Za is the atomic number of atom A and A is the electron density (see Atoms in Molecules) assigned to A. The calculation of q depends on the partitioning of the electron density. In the framework of Mulliken population analysis (see Electronic Wavefunctions Analysis), cja is related to the gross atomic population H q, where q is the gross... 

Atomic numbers of atoms directly attached to the stereocenter have to compared, and the higher priority... 

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