26 May 07 Einstein’s Philosophy of Science
About ten year ago I spoke with Einstein about the astonishing fact that so ministers of various denominations are strongly interested in the theory of relativity. Einstein said that according to his estimation there are more clergymen interested in relativity than physicists. A little puzzle I asked him how he would explain this strange fact. He answered, a little smiling, “Because clergymen are interested in the general laws of nature and the physicists, very often, are not“…… (the rest please the paper)
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11 May 07 Ab-Initio Molecular Dynamics Simulation: Theory and Implementation
by Dominic Marx et.al
Abstract:
The rapidly growing field of ab initio molecular dynamics is reviewed in the spirit of a series of lectures given at the Winterschool 2000 at the John von Neumann Institute for Computing, Juelich. Several such olecular dynamics schemes are compared which arise from following various approximations to the fully coupled Schroedinger equation for electrons and nuclei. Special focus is given to the Car-Parrinello method with discussion of both strengths and weaknesses in addition to its range of applicability. To shed light upon why the Car-Parrinello approach works several alternate perspectives of the underlying ideas are presented. The implementation of ab initio molecular dynamics within the framework of plane wave- pseudopotential density functional theory is given in detail, including diagonalization and minimization techniques as required for the Born-Oppenheimer variant. Efficient algorithms for the most important computational kernel routines are presented. The adaptation of these routines to distributed memory parallel computers is discussed using the implementation within the computer code CPMD as an example. Several advanced techniques from the field of molecular dynamics, (constant temperature dynamics, constant pressure dynamics) and electronic structure theory (free energy functional, excited states) are introduced. The combination of the path integral method with ab initio molecular dynamics is presented in detail, showing its limitations and possible extensions. Finally, a wide range of applications from materials science to biochemistry is listed, which shows the enormous potential of ab initio molecular dynamics for both explaining and predicting properties of molecules and materials on an atomic scale.
The paper could be download here (pdf-file)
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