Optimization of Geometric Structures of New Materials on Parallel Computers
Abstract
Ab inito molecular dynamics (AIMD) simulation code based on the planewave pseudopotential local density functional method have been developed. With the new codes, it is possible to simulate geometric, dynamical and electronic properties of molecules and polymers containing more than 200 atoms from first principle. In addition, they allow the use of both periodic and freespace boundary conditions. Extended systems such as polymers can be simulated with periodic boundary conditions, whereas finite-size systems including charged systems can be calculated with freespace boundary conditions. Various benchmark tests demonstrate the high degree of accuracy and efficiency of parallel processing. This code has been applied to the simulation of semiconducting polymers with large repeat cells. The most significant problem with the application of AIMD to a wider variety of high performance materials is the poor convergence of the planewave basis that is used in all the present methods. For a system that have 2nd period elements nitrogen, oxygen and fluorine or the transition metals, AIMD calculations based on plane waves are very inefficient. We have been developing a new method which is based on the direct descretation of space. There are a number of difficulties with the application of this approach, but we believe that we have finally identified a correct path to an efficient algorithm.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 15, 1998
- Accession Number
- ADA352281
Entities
People
- Beth Ong
- John H. Weare
- Ryoichi Kawai
Organizations
- University of California, San Diego