10.3. SRP Soft

10.3.1. Functional Form

The SRP soft potential has the functional form:

\(E={{C}_{ij}}\left( 1-\frac{{{R}_{ij}}}{{{R}_{c}}} \right)\)

The force-field parameters for this potential and units are given by:

Equation Symbol Parameter Definition Units
\(C_{ij}\) Coefficient for repulsive force force
\(R_{c}\) Cutoff distance value length

10.3.2. XML Schema

The XML schema for the soft SRP 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
Coefficient for repulsive force \(C_{ij}\) c_ij
Cutoff distance value \(R_{c}\) r_c

The general attributes (describing the entire data set) are given by:

General Attributes Cardinality Value/Definition
style Fixed SRP
formula Fixed c_ij*(1-r/r_c)
c_ij-units Required Enumerations specified in schema
r_c-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.