SQUARE45

Let

P

be a polymer chain defined by a sequence of

N

structural units (monomers)

m_i

, where

i \in \{1, 2, \dots, N\}

. The polymer structure is represented by the sequence of connected monomers:

P = m_1 - m_2 - \dots - m_N

. The connectivity is governed by covalent bonds, represented by the Hamiltonian

H_{bond} = \sum_{i=1}^{N-1} V_{covalent}(\mathbf{r}_i, \mathbf{r}_{i+1})

, where

\mathbf{r}_i

are the spatial coordinates of the

i

-th monomer, and

V_{covalent}

is the potential energy associated with the bond linking

m_i

and

m_{i+1}

. The chain topology is characterized by the repeating unit

R

, such that

P \approx (R)^N

Definition: Polymer