Accurate molecular dynamics and nuclear quantum effects at low cost by multiple steps in real and imaginary time: Using density functional theory to accelerate wavefunction methods
The development and implementation of increasingly accurate methods for electronic structure calculations mean that, for many atomistic simulation problems, treating light nuclei as classical particles is now one of the most serious approximations. Even though recent developments have significantly reduced the overhead for modeling the quantum nature of the nuclei, the cost is still prohibitive when combined with advanced electronic structure methods. Here we present how multiple time step integrators can be combined with ring-polymer contraction techniques (effectively, multiple time stepping in imaginary time) to reduce virtually to zero the overhead of modelling nuclear quantum effects, while describing inter-atomic forces at high levels of electronic structure theory. This is demonstrated for a combination of MP2 and semi-local DFT applied to the Zundel cation. The approach can be seamlessly combined with other methods to reduce the computational cost of path integral calculations, such as high-order factorizations of the Boltzmann operator or generalized Langevin equation thermostats.
- OSTI ID:
- 22493712
- Journal Information:
- Journal of Chemical Physics, Vol. 144, Issue 5; Other Information: (c) 2016 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-9606
- Country of Publication:
- United States
- Language:
- English
Similar Records
Accelerated path integral methods for atomistic simulations at ultra-low temperatures
Ab initio molecular dynamics with nuclear quantum effects at classical cost: Ring polymer contraction for density functional theory
Related Subjects
GENERAL PHYSICS
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
APPROXIMATIONS
CATIONS
DENSITY FUNCTIONAL METHOD
ELECTRONIC STRUCTURE
IMPLEMENTATION
INTERATOMIC FORCES
LANGEVIN EQUATION
MOLECULAR DYNAMICS METHOD
PATH INTEGRALS
POLYMERS
THERMOSTATS
WAVE FUNCTIONS