Accession Number:

ADA191663

Title:

A Constraint Algorithm for Maintaining Rigid Bonds in Molecular Dynamics Simulations of Large Molecules.

Descriptive Note:

Memorandum rept.,

Corporate Author:

NAVAL RESEARCH LAB WASHINGTON DC

Personal Author(s):

• Lambrakos, S. G.
• Boris, J. P.
• Oran, E. S.
• Chandrasekhar, I.
• Nagumo, M.

Report Date:

1988-03-04

Pagination or Media Count:

39.0

Abstract:

We present an efficient new algorithm, the Multiple Constraint Force MCF algorithm, for maintaining fixed distances in molecular dynamics simulations of polyatomic molecules. A reversible leapfrog integration scheme is modified to calculate the constraint forces required to maintain fixed interparticle distances usually corresponding to chemical bonds. The procedure is exact for diatomic systems. It converges in a small number of iterations for polyatomic molecules and scales linearly with the number of bonds to be kept rigid. The MCF algorithm, like the SHAKE algorithm, iteratively corrects the constrained equations of motion. Rather than successively correcting particle positions or inverting a matrix, however, the MCF algorithm iteratively correct the constraint forces required to maintain the fixed distances. Keywords Constraint algorithm, Molecules dynamics, Polyatomic molecules.

Descriptors:

• *ALGORITHMS
• *DYNAMICS
• *EQUATIONS OF MOTION
• *MOLECULES
• BONDED JOINTS
• CHEMICAL BONDS
• DIATOMIC MOLECULES
• EFFICIENCY
• INTEGRATION
• ITERATIONS
• MOLECULAR PROPERTIES
• PARTICLES
• POLYATOMIC MOLECULES
• RIGIDITY
• SHAKING
• SIMULATION

Subject Categories:

• Physical Chemistry

Distribution Statement:

APPROVED FOR PUBLIC RELEASE