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  2. Zero-point energy - Wikipedia

    en.wikipedia.org/wiki/Zero-point_energy

    Zero-point energy (ZPE) is the lowest possible energy that a quantum mechanical system may have. Unlike in classical mechanics, quantum systems constantly fluctuate in their lowest energy state as described by the Heisenberg uncertainty principle. [1] Therefore, even at absolute zero, atoms and molecules retain some vibrational motion.

  3. Vienna Ab initio Simulation Package - Wikipedia

    en.wikipedia.org/wiki/Vienna_Ab_initio...

    An early version of VASP was called VAMP. [11] VASP is currently being developed by Georg Kresse; recent additions include the extension of methods frequently used in molecular quantum chemistry to periodic systems. VASP is currently used by more than 1400 research groups in academia and industry worldwide on the basis of software licence ...

  4. Quantum chemistry composite methods - Wikipedia

    en.wikipedia.org/wiki/Quantum_chemistry...

    The last two terms are zero-point energy corrections scaled with a factor of 0.989 to account for deficiencies in the harmonic approximation and spin-orbit corrections considered only for atoms. The Correlation Consistent Composite Approach is available as a keyword in NWChem [ 18 ] and GAMESS (ccCA-S4 and ccCA-CC(2,3)) [ 19 ]

  5. Ground state - Wikipedia

    en.wikipedia.org/wiki/Ground_state

    Energy levels for an electron in an atom: ground state and excited states. After absorbing energy, an electron may jump from the ground state to a higher-energy excited state. The ground state of a quantum-mechanical system is its stationary state of lowest energy; the energy of the ground state is known as the zero-point energy of the system.

  6. QED vacuum - Wikipedia

    en.wikipedia.org/wiki/QED_vacuum

    It is the lowest energy state (the ground state) of the electromagnetic field when the fields are quantized. [1] When the Planck constant is hypothetically allowed to approach zero, QED vacuum is converted to classical vacuum, which is to say, the vacuum of classical electromagnetism. [2] [3]

  7. Quantum vacuum state - Wikipedia

    en.wikipedia.org/wiki/Quantum_vacuum_state

    The video of an experiment showing vacuum fluctuations (in the red ring) amplified by spontaneous parametric down-conversion.. If the quantum field theory can be accurately described through perturbation theory, then the properties of the vacuum are analogous to the properties of the ground state of a quantum mechanical harmonic oscillator, or more accurately, the ground state of a measurement ...

  8. Energy minimization - Wikipedia

    en.wikipedia.org/wiki/Energy_minimization

    In the field of computational chemistry, energy minimization (also called energy optimization, geometry minimization, or geometry optimization) is the process of finding an arrangement in space of a collection of atoms where, according to some computational model of chemical bonding, the net inter-atomic force on each atom is acceptably close to zero and the position on the potential energy ...

  9. Casimir effect - Wikipedia

    en.wikipedia.org/wiki/Casimir_effect

    In this case, the correct way to find the zero-point energy of the field is to sum the energies of the standing waves of the cavity. To each and every possible standing wave corresponds an energy; say the energy of the n th standing wave is E n. The vacuum expectation value of the energy of the electromagnetic field in the cavity is then