Related Experiment Video
Updated: Mar 24, 2026
05:30
Large Scale Energy Efficient Sensor Network Routing Using a Quantum Processor Unit
Published on: September 8, 2023
1.2K
Understanding and improving the efficiency of full configuration interaction quantum Monte Carlo
W A Vigor1, J S Spencer2, M J Bearpark1
1Department of Chemistry, Imperial College London, Exhibition Road, London SW7 2AZ, United Kingdom.
The Journal of Chemical Physics
|March 10, 2016
Summary
We explored statistical errors in quantum Monte Carlo methods. A minimized inefficiency was found within a specific parameter range, suggesting basis set choice impacts results.
Area of Science:
- Computational quantum chemistry
- Stochastic methods
Background:
- Full configuration interaction quantum Monte Carlo (FCIQMC) is a powerful method for electronic structure calculations.
- Statistical errors are a key challenge in stochastic quantum methods.
Purpose of the Study:
- To investigate the behavior of statistical errors in FCIQMC.
- To identify optimal sampling parameters for minimizing statistical error.
Main Methods:
- Defined and analyzed 'inefficiency' as statistical error per particle and time step.
- Varied parameters controlling stochastic sampling in FCIQMC.
Main Results:
- Identified a parameter regime where inefficiency is minimized.
- Found inefficiency increases sublinearly with Hilbert space size.
- Demonstrated that localizing Hartree-Fock orbitals reduces inefficiency.
Conclusions:
- The choice of basis set significantly impacts FCIQMC performance beyond the sign problem.
- Optimizing sampling parameters and basis sets is crucial for accurate and efficient quantum Monte Carlo calculations.
Related Concept Videos
01:23Equilibrium Conditions for a Particle
2.6K
When an object is in equilibrium, it is either at rest or moving with a constant velocity. There are two types of equilibrium: static and dynamic. Static equilibrium occurs when an object is at rest, while dynamic equilibrium occurs when an object is moving with a constant velocity. In both cases, there must be a balance of forces acting on the object.
To understand the concept of equilibrium, let us first consider the forces acting on an object. When different forces act on an object, they can...
To understand the concept of equilibrium, let us first consider the forces acting on an object. When different forces act on an object, they can...
2.6K
01:12Fermi Level Dynamics
962
The vacuum level denotes the energy threshold required for an electron to escape from a material surface. It is usually positioned above the conduction band of a semiconductor and acts as a benchmark for comparing electron energies within various materials.
Electron affinity in semiconductors refers to the energy gap between the minimum of its conduction band and the vacuum level and it is a critical parameter in determining how easily a semiconductor can accept additional electrons.
The work...
Electron affinity in semiconductors refers to the energy gap between the minimum of its conduction band and the vacuum level and it is a critical parameter in determining how easily a semiconductor can accept additional electrons.
The work...
962
02:45The Quantum-Mechanical Model of an Atom
61.5K
Shortly after de Broglie published his ideas that the electron in a hydrogen atom could be better thought of as being a circular standing wave instead of a particle moving in quantized circular orbits, Erwin Schrödinger extended de Broglie’s work by deriving what is now known as the Schrödinger equation. When Schrödinger applied his equation to hydrogen-like atoms, he was able to reproduce Bohr’s expression for the energy and, thus, the Rydberg formula governing hydrogen spectra.
61.5K
01:20Maxwell-Boltzmann Distribution: Problem Solving
3.1K
Individual molecules in a gas move in random directions, but a gas containing numerous molecules has a predictable distribution of molecular speeds, which is known as the Maxwell-Boltzmann distribution, f(v).
This distribution function f(v) is defined by saying that the expected number N (v1,v2) of particles with speeds between v1 and v2 is given by
This distribution function f(v) is defined by saying that the expected number N (v1,v2) of particles with speeds between v1 and v2 is given by
3.1K
01:29Mechanistic Models: Compartment Models in Algorithms for Numerical Problem Solving
393
Mechanistic models play a crucial role in algorithms for numerical problem-solving, particularly in nonlinear mixed effects modeling (NMEM). These models aim to minimize specific objective functions by evaluating various parameter estimates, leading to the development of systematic algorithms. In some cases, linearization techniques approximate the model using linear equations.
In individual population analyses, different algorithms are employed, such as Cauchy's method, which uses a...
In individual population analyses, different algorithms are employed, such as Cauchy's method, which uses a...
393
01:23Stability of Equilibrium Configuration
939
Understanding the stability of equilibrium configurations is a fundamental part of mechanical engineering. In any system, there are three distinct types of equilibrium: stable, neutral, and unstable.
A stable equilibrium occurs when a system tends to return to its original position when given a small displacement, and the potential energy is at its minimum. An example of a stable equilibrium is when a cantilever beam is fixed at one end and a weight is attached to the other end. If the weight...
A stable equilibrium occurs when a system tends to return to its original position when given a small displacement, and the potential energy is at its minimum. An example of a stable equilibrium is when a cantilever beam is fixed at one end and a weight is attached to the other end. If the weight...
939