These techniques avoid all problems occurring in the original Car-Parrinello method which is based on the simultaneous integration of electronic and ionic equations of motion. The approach implemented in VAMP/VASP is based on a finite-temperature local-density approximation (with the free energy as variational quantity) and an exact evaluation of the instantaneous electronic ground state at each MD-step using efficient matrix diagonalization schemes and an efficient Pulay mixing. VAMP/VASP is a package for performing ab-initio quantum-mechanical molecular dynamics (MD) using pseudopotentials and a plane wave basis set. If you are interested in this package please contact Prof.
#Quantumwise dielectric constant for free#
(Licence Details: available for free for academic users. Calculations can be efficiently run in parallel on hundreds or thousands of CPUs. For structure relaxations and energy evaluations, used as part of structure prediction algorithm, USPEX is interfaced with external codes (VASP, SIESTA, GULP, MD++). Simulations using other, in general less efficient, methods (random sampling, particle swarm optimization) are also possible. Structure prediction is made particularly efficient by the use of special variation operators, preconditioning schemes, and structure fingerprint functions. It can also simultaneously search for stable structures and compositions in multicomponent systems.
![quantumwise dielectric constant quantumwise dielectric constant](https://ars.els-cdn.com/content/image/1-s2.0-S0045782521005703-gr23.jpg)
The efficient structure searching algorithm enables prediction of large and complex structures that possess the greatest stability at given conditions or desired physical properties.
![quantumwise dielectric constant quantumwise dielectric constant](https://image.slidesharecdn.com/listofdielectricconstantsen-160504082240/95/list-of-dielectric-constants-4-638.jpg)
USPEX is a code for predicting the structure of crystals, surfaces and nanoparticles using a specifically developed evolutionary algorithm (also called USPEX).