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NIH: National Institute of Diabetes and Digestive and Kidney Diseases NIH: National Institute of Diabetes and Digestive and Kidney Diseases

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Next: Empirical Energy Functions Up: XPLOR Interface Manual Previous: Virus Structures or Structures


Energy Function

The XPLOR energy function can be grouped into two different classes:
\begin{displaymath}
E_{TOTAL} = E_{EMPIRICAL} + E_{EFFECTIVE}
\end{displaymath} (4.1)

$E_{EMPIRICAL}$ describes the energy of the molecule(s) through an empirical energy function described below. $E_{EFFECTIVE}$ comprises restraining energy terms that use experimental information or other information:
$\displaystyle E_{EFFECTIVE}$ $\textstyle =$ $\displaystyle E_{XREF} + E_{NOE} + E_{HARM} +$  
    $\displaystyle E_{CDIH} + E_{NCS} + E_{DG} + E_{RELA} + E_{PLAN}$ (4.2)

The $E_{XREF}$, $E_{NOE}$, $E_{HARM}$, $E_{CDIH}$, $E_{NCS}$, $E_{DG}$, $E_{RELA}$, and $E_{PLAN}$ terms are described in Chapters 13, 20, 7.1, 7.2, 18, 37, 39, and 7.3, respectively.



Subsections
  • Empirical Energy Functions
  • Conformational Energy Terms
  • Nonbonded Energy Terms
    • Van der Waals Function
    • Electrostatic Function
    • Intramolecular Interactions
    • Crystallographic Symmetry Interactions
    • Non-crystallographic Symmetry Interactions

  • The Explicit Hydrogen-Bond Term
  • Turning Energy Terms On or Off
    • Syntax
    • Requirements
    • Example: Turn On Energy Terms for X-ray Refinement

  • Energy Statement
    • Syntax
    • Requirements
    • Examples

  • Energy Calculation between Selected Atoms
    • Syntax
    • Requirements
    • Example: Interchain Interaction Energy


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