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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11
votes
1answer
238 views

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 ...
16
votes
3answers
435 views

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 ...
8
votes
1answer
100 views

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"?
5
votes
0answers
47 views

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?
7
votes
1answer
84 views

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 ...
17
votes
0answers
93 views

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 ...
5
votes
1answer
104 views

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 ...