minor changes

[lectures/latex.git] / posic / thesis / basics.tex

diff --git a/posic/thesis/basics.tex b/posic/thesis/basics.tex
index fe77c41..acc423c 100644 (file)
--- a/posic/thesis/basics.tex
+++ b/posic/thesis/basics.tex
@@ -87,8 +87,8 @@ Examples of single particle potentials are the gravitational force or an electri
 $U_2$ is a two body pair potential which only depends on the distance $r_{ij}$ between the two atoms $i$ and $j$.
 If not only pair potentials are considered, three body potentials $U_3$ or many body potentials $U_n$ can be included.
 Usually these higher order terms are avoided since they are not easy to model and it is rather time consuming to evaluate potentials and forces originating from these many body terms.
-Ordinary pair potentials have a close-packed structure like face-centered cubic (FCC) or hexagonal close-packed (HCP) as a ground state.
-A pair potential is, thus, unable to describe properly elements with other structures than FCC or HCP.
+Ordinary pair potentials have a close-packed structure like face-centered cubic (fcc) or hexagonal close-packed (hcp) as a ground state.
+A pair potential is, thus, unable to describe properly elements with other structures than fcc or hcp.
 Silicon and carbon for instance, have a diamond and zincblende structure with four covalently bonded neighbors, which is far from a close-packed structure.
 A three body potential has to be included for these types of elements.