Rules
Firstly, the electrons are arranged in to a sequence of groups in order of increasing principal quantum number n, and for equal n in order of increasing azimuthal quantum number l, except that s- and p- orbitals are kept together.
- etc.
Each group is given a different shielding constant which depends upon the number and types of electrons in those groups preceding it.
The shielding constant for each group is formed as the sum of the following contributions:
- An amount of 0.35 from each other electron within the same group except for the group, where the other electron contributes only 0.30.
- If the group is of the type, an amount of 0.85 from each electron with principal quantum number (n) one less and an amount of 1.00 for each electron with an even smaller principal quantum number
- If the group is of the or, type, an amount of 1.00 for each electron inside it. This includes i) electrons with a smaller principal quantum number and ii) electrons with an equal principal quantum number and a smaller azimuthal quantum number (l)
In tabular form, the rules are summarized as:
| Group | Other electrons in the same group | Electrons in group(s) with principal quantum number n and azimuthal quantum number < l | Electrons in group(s) with principal quantum number n-1 | Electrons in all group(s) with principal quantum number < n-1 |
|---|---|---|---|---|
| 0.30 | N/A | N/A | N/A | |
| 0.35 | N/A | 0.85 | 1 | |
| or | 0.35 | 1 | 1 | 1 |
Read more about this topic: Slater's Rules
Famous quotes containing the word rules:
“There are two great rules in life, the one general and the other particular. The first is that every one can in the end get what he wants if he only tries. This is the general rule. The particular rule is that every individual is more or less of an exception to the general rule.”
—Samuel Butler (1835–1902)
“Ideas about life organize perception; names of emotions organize sensations; rules of syntax organize thought. But pain comes on its own.”
—Mason Cooley (b. 1927)
“The early Christian rules of life were not made to last, because the early Christians did not believe that the world itself was going to last.”
—George Bernard Shaw (1856–1950)