5.9. Tabular Dihedral¶
5.9.1. Tabular Form¶
The tabular dihedral potential has the parameters:
| Parameter | Parameter Definition | Units |
| N | Number of tabulated values | N/A |
| NOF | Allows omission of forces (energy derivatives) in the table | N/A |
| DEGREES | Specify degrees as units for the angles | N/A |
| RADIANS | Specify radians as units for the angles | N/A |
| CHECKU | File to save interpolated energy table | N/A |
| CHECKF | File to save interpolated force table | N/A |
The tabular dihedral potential has the tabulated values:
| index | angle | energy | derivative |
| i_1 | a_1 | e_1 | de_1 |
| … | … | … | … |
| i_N | a_N | e_n | de_N |
5.9.2. XML Schema¶
The XML schema for the tabular dihedral potential has the following representation (design mode representation using Liquid XML Studio):
The relationship between the parameters/symbols and XML schema notations are given by:
| Parameter Definition | Parameter/Symbol | Schema Notation |
| Atom type of atom [i] | \(i\) | AT-1 |
| Atom type of atom [j] | \(j\) | AT-2 |
| Atom type of atom [k] | \(k\) | AT-3 |
| Section identifying keyword | N/A | keyword |
| Number of tabulated values | N | N |
| Allows omission of forces in the table | NOF | NOF |
| Specify degrees as units for the angles | DEGREES | angle-units |
| Specify radians as units for the angles | RADIANS | angle-units |
| File to save interpolated energy table | CHECKU | CHECKU |
| File to save interpolated force table | CHECKF | CHECKF |
| Index | index | index |
| Angle | angle | angle |
| Energy | energy | energy |
| Derivate of energy | derivative | energy-diff |
The general attributes (describing the entire data set) are given by:
| General Attributes | Cardinality | Value/Definition |
| style | Fixed | Tabular |
| angle-units | Required | Enumerations specified in schema |
| energy-units | Required | Enumerations specified in schema |
| energy-diff-units | Required | Enumerations specified in schema |
| 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.