TY  - GEN
A1  - Bornemann, Folkmar A.
A1  - Schütte, Christof
T1  - Adaptive Accuracy Control for Microcanonical Car-Parrinello Simulations
N2  - The Car-Parrinello (CP) approach to ab initio molecular dynamics serves as an approximation to time-dependent Born-Oppenheimer (BO) calculations. It replaces the explicit minimization of the energy functional by a fictitious Newtonian dynamics and therefore introduces an artificial mass parameter $\mu$ which controls the electronic motion. A recent theoretical investigation shows that the CP-error, i.e., the deviation of the CP--solution from the BO-solution {\em decreases} like $\mu^{1/2}$ asymptotically. Since the computational effort {\em increases} like $\mu^{-1/2}$, the choice of $\mu$ has to find a compromise between efficiency and accuracy. The asymptotical result is used in this paper to construct an easily implemented algorithm which automatically controls $\mu$: the parameter $\mu$ is repeatedly adapted during the simulation by choosing $\mu$ as large as possible while pushing an error measure below a user-given tolerance. The performance and reliability of the algorithm is illustrated by a typical example.
T3  - ZIB-Report - SC-96-20 
Y1  - 1996
UR  - https://opus4.kobv.de/opus4-zib/frontdoor/index/index/docId/231
UR  - https://nbn-resolving.org/urn:nbn:de:0297-zib-2311
ER  -