Electron related functions and classes

In sisl electronic structure calculations are relying on routines specific for electrons. For instance density of states calculations from electronic eigenvalues and other quantities.

This module implements the necessary tools required for calculating DOS, PDOS, band-velocities and spin moments of non-collinear calculations. One may also plot real-space wavefunctions.

DOS(E, eig[, distribution])	Calculate the density of states (DOS) for a set of energies, E, with a distribution function
PDOS(E, eig, state[, S, distribution, spin])	Calculate the projected density of states (PDOS) for a set of energies, E, with a distribution function
velocity(state, dHk[, energy, dSk, degenerate])	Calculate the velocity of a set of states
velocity_matrix(state, dHk[, energy, dSk, …])	Calculate the velocity matrix of a set of states
berry_phase(contour[, sub, eigvals, closed, …])	Calculate the Berry-phase on a loop using a predefined path
wavefunction(v, grid[, geometry, k, spinor, …])	Add the wave-function (Orbital.psi) component of each orbital to the grid
spin_moment(state[, S])	Calculate the spin magnetic moment (also known as spin texture)
spin_squared(state_alpha, state_beta[, S])	Calculate the spin squared expectation value between two spin states

Supporting classes

Certain classes aid in the usage of the above methods by implementing them using automatic arguments.

For instance, the PDOS method requires the overlap matrix in non-orthogonal basis sets at the \(k\)-point corresponding to the eigenstates. Hence, the argument S must be \(\mathbf S(\mathbf k)\). The EigenstateElectron class automatically passes the correct S because it knows the states \(k\)-point.

CoefficientElectron(c[, parent])	Coefficients describing some physical quantity related to electrons
StateElectron(state[, parent])	A state describing a physical quantity related to electrons
StateCElectron(state, c[, parent])	A state describing a physical quantity related to electrons, with associated coefficients of the state
EigenvalueElectron(c[, parent])	Eigenvalues of electronic states, no eigenvectors retained
EigenvectorElectron(state[, parent])	Eigenvectors of electronic states, no eigenvalues retained
EigenstateElectron(state, c[, parent])	Eigen states of electrons with eigenvectors and eigenvalues.