Flory convention

The Flory convention for defining the variables involved on modeling the position vectors of atoms in macromolecules it is often necessary to convert from Cartesian coordinates (x,y,z) to generalized coordinates. It is named after nobel prize-winning Paul Flory.^[1][2]

As an example of its use, a peptide bond can be described by the x,y,z positions of every atom in this bond or the Flory convention can be used. Here one must know the bond lengths $l_{i}$, bond angles $\theta _{i}$, and the dihedral angles $\phi _{i}$ (note that the sequence of dihedral angles is specified using angle 0 as trans). Applying a vector conversion from the Cartesian coordinates to the generalized coordinates will describe the same three-dimensional structure using the Flory convention.

References

1. Flory PJ (1941). "Molecular Size Distribution in Three-Dimensional Polymers: I, Gelation". J. Amer. Chem. Soc. 63 (11): 3083. doi:10.1021/ja01856a061.
2. Morris PJT (1986). "Polymer Pioneers: A Popular History of the Science and Technology of Large Molecules". Center for History of Chemistry, Philadelphia.