# Questions tagged [quantum-dynamics]

Questions about quantum dynamics methods (MCTDH, t-DMRG, Feynman integral dynamics, etc.), or in some cases about quantum dynamics itself. Quantum dynamics is usually the dynamics of wavefunctions, density matrices, reduced density matrices, Wigner functions, or properties/expectation-values.

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### What matter modeling problems could be solved with 100 error-corrected qubits?

IBM, Infleqtion, QuEra, and other quantum hardware companies have announced roadmaps where they expect to have 100 or more error-corrected qubits by the end of the decade. It seems increasingly likely ...
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1 vote
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### Looking for resources to learn quantum dynamics at a preliminary graduate level

I am currently a senior year chemistry undergraduate with a keen interest towards pursuing a PhD in the fields of Quantum Dynamics. I have a strong background in mathematics and undergraduate quantum ...
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### Time Evolution of the Hartree-Fock Wave Function

The Hartree-Fock Hamiltonian is given by $$\hat{H} = \sum_i \hat{h}_i + \frac{1}{2}\sum_i\sum_j \left[\hat{J}_{ij} - \hat{K}_{ij}\right]$$ and by choosing a basis, the Hamiltonian can be written in ...
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### How can one determine the time-step for imaginary time evolution?

The real-time evolution of a quantum system described by the state $\psi(t)$ is formally given by, $$\psi(t+\Delta t) = \exp^{- i \hat{H} \Delta t / \hbar} \psi(t)\tag{1}$$ For dynamical simulations ...
3k views

### Can DFT simulate chemical reactions?

I was wondering, can you simulate the chemical reaction between two or more molecules using DFT? If not, what numerical method is usually used for this?
263 views

### What's the role of Berry curvature in quantized Hall effects? [closed]

Cross-posted and answered at Physics.SE. The quantized versions of the Hall effect include (ignoring fractional quantum Hall effect): Quantum Hall effect; Quantum anomalous Hall effect; Quantum spin ...
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### How to calculate electronic circular dichroism (ECD) spectra from MCTDH? [closed]

Electronic circular dichroism (ECD) spectra is commonly used in organic chemistry to characterize chiral molecules. Here the question is how to simulate ECD spectra using MCTDH (Multi-configurational ...
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### How to calculate state population from MCTDH?

In this reference, the author investigates electronic population dynamics from a MCTDH calculation. My question is how to generate state populations over time from an MCTDH calculation? Is there a ...
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284 views

### What are some of the biggest theoretical and computational challenges in Condensed Phase Chemistry?

What are some of the biggest open-questions / challenges in Condensed Phase theory and computation? What efforts are being done to answer them? I realize Condensed Phase chemistry is a huge field, but ...
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### How exact is DFT, really?

It is often claimed (e.g. here), that Density Functional Theory is in principle exact. This seems to be a very strong statement to me. Are all current limitations only of a technical nature rather ...
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### References for Molecular Dynamics?

I am new to the world of Molecular Dynamics (zero practical experience), and I know that a starting point to really go into the back-bone of MD is Statistical Mechanics (took a semester course in ...
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### What is the "overcoherence problem" in Ehrenfest dynamics?

I am a novice in Ehrenfest dynamics and would like to know why Ehrenfest dynamics suffers from the "overcoherence problem"?
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### What is the difference between Ehrenfest dynamics and Born-Oppenheimer Molecular Dynamics? [duplicate]

What is the fundamental difference(s) between Ehrenfest dynamics and Born-Oppenheimer MD? Also, in what situation(s) or case(s) one is preferred than the other one?
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### What are the types of Quantum Molecular Dynamics (QMD)?

In similar spirit to recent questions on Quantum Monte Carlo, ab-initio Molecular Dynamics, types of SCF, and others, I would like to ask: What are the types of Quantum Molecular Dynamics (QMD)? As I ...
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### Quadrature over three Euler Angles for orientation averaging

Does anybody know about an accurate quadrature rule over three Euler angles $\theta, \phi, \chi$? I am trying to calculate the average value of an arbitrary function $f(\theta, \phi, \chi)$ for a ...
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### How is MCTDH derived?

In the multi-configurational time-dependent Hartree (MCTDH) method, the equation of motion is derived from the time-dependent Schrödinger equation by substituting the wavefunction ansatz expanded in a ...
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