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  2. Plane wave - Wikipedia

    en.wikipedia.org/wiki/Plane_wave

    The term is also used, even more specifically, to mean a "monochromatic" or sinusoidal plane wave: a travelling plane wave whose profile () is a sinusoidal function. That is, (,) = ⁡ (() +) The parameter , which may be a scalar or a vector, is called the amplitude of the wave; the scalar coefficient is its "spatial frequency"; and the scalar is its "phase shift".

  3. Basis set (chemistry) - Wikipedia

    en.wikipedia.org/wiki/Basis_set_(chemistry)

    In theoretical and computational chemistry, a basis set is a set of functions (called basis functions) that is used to represent the electronic wave function in the Hartree–Fock method or density-functional theory in order to turn the partial differential equations of the model into algebraic equations suitable for efficient implementation on a computer.

  4. Vienna Ab initio Simulation Package - Wikipedia

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

    The Vienna Ab initio Simulation Package, better known as VASP, is a package written primarily in Fortran for performing ab initio quantum mechanical calculations using either Vanderbilt pseudopotentials, or the projector augmented wave method, and a plane wave basis set. [2]

  5. Bloch's theorem - Wikipedia

    en.wikipedia.org/wiki/Bloch's_theorem

    A Bloch wave function (bottom) can be broken up into the product of a periodic function (top) and a plane-wave (center). The left side and right side represent the same Bloch state broken up in two different ways, involving the wave vector k 1 (left) or k 2 (right). The difference (k 1 − k 2) is a reciprocal lattice vector. In all plots, blue ...

  6. Wave - Wikipedia

    en.wikipedia.org/wiki/Wave

    A plane wave is an important mathematical idealization where the disturbance is identical along any (infinite) plane normal to a specific direction of travel. Mathematically, the simplest wave is a sinusoidal plane wave in which at any point the field experiences simple harmonic motion at one frequency.

  7. Linear combination of atomic orbitals - Wikipedia

    en.wikipedia.org/wiki/Linear_combination_of...

    The atomic orbitals used are typically those of hydrogen-like atoms since these are known analytically i.e. Slater-type orbitals but other choices are possible such as the Gaussian functions from standard basis sets or the pseudo-atomic orbitals from plane-wave pseudopotentials. Example of a molecular orbital diagram.

  8. Matter wave - Wikipedia

    en.wikipedia.org/wiki/Matter_wave

    Top: plane wave. Bottom: wave packet. When I conceived the first basic ideas of wave mechanics in 1923–1924, I was guided by the aim to perform a real physical synthesis, valid for all particles, of the coexistence of the wave and of the corpuscular aspects that Einstein had introduced for photons in his theory of light quanta in 1905.

  9. Quantum ESPRESSO - Wikipedia

    en.wikipedia.org/wiki/Quantum_ESPRESSO

    The core plane wave DFT functions of QE are provided by the PWscf component (PWscf previously existed as an independent project). PWscf (Plane-Wave Self-Consistent Field) is a set of programs for electronic structure calculations within DFT and density functional perturbation theory, using plane wave basis sets and pseudopotentials.