What does total number of atomic sites mean ?

[potatowhisperer]

i know this might seem as a very simple question , but i am confused :
in order to calculate the total number of vacancies we need the total number of atomic sites N , and since N depends on the density of the material , then N refers to the number of atoms , right ? what confuses me is the word site , because it implies :(the total number of atoms + number of vacancies) .
so my question is : does the total number of sites include vacancies ?

 

[drvrm]

i know this might seem as a very simple question , but i am confused :
in order to calculate the total number of vacancies we need the total number of atomic sites N , and since N depends on the density of the material , then N refers to the number of atoms , right ? what confuses me is the word site , because it implies :(the total number of atoms + number of vacancies) .
so my question is : does the total number of sites include vacancies ?

pl. give the context in which you are looking at the vacancies.

If you are analysing defects in crystal's structure - vacancies are separately counted - and N represents the total no. of sites where defects can have potential role and its counted as number of lattice sites where atom can be placed - its the fraction N(D)/N which is measured.
N is also named as Potential defect sites. so if you take the total no. of lattice sites it serves the purpose.

 

[potatowhisperer]

Thank you so much , I reread your replie so many times and you explained it so clearly , thank you .