3.3. Harmonic Bond¶
3.3.1. Functional Form¶
The harmonic bond potential has the functional form:
\(E = {K_{ij}} \cdot \left( {{R_{ij}} - {R_{0,ij}}} \right)^{2}\)
The force-field parameters for this potential and units are given by:
Equation Symbol | Parameter Definition | Units |
\(K_{ij}\) | Bond coefficient for atoms [i,j] | energy/length^2 |
\(R_{0,ij}\) | Equilibrium bond length for atoms [i,j] | length |
3.3.2. XML Schema¶
The XML schema for the harmonic bond potential has the following representation (design mode representation using Liquid XML Studio):
The relationship between the equation symbols and XML schema notations are given by:
Parameter Definition | Equation Symbol | Schema Notation |
Atom type of atom [i] | \(i\) | AT-1 |
Atom type of atom [j] | \(j\) | AT-2 |
Bond coefficient for atoms [i,j] | \(K_{ij}\) | K |
Equilibrium bond length for atoms [i,j] | \(R_{0,ij}\) | R0 |
The general attributes (describing the entire data set) are given by:
General Attributes | Cardinality | Value/Definition |
style | Fixed | Harmonic |
formula | Fixed | K*(R_R0)^2 |
K-units | Required | Enumerations specified in schema |
R0-units | Required | Enumerations specified in schema |
The specific attributes (attached to each set of parameters) are given by:
Specific Attributes | Cardinality | Value/Definition |
comment | Optional | Comment attached to parameter set |
version | Optional | Version number of parameter set |
reference | Optional | Reference attached to parameter set |
Note that an XML document will be rejected from being entered into the WebFF database if a required attribute is left unspecified.