Documentation

Algorithms

Name	Description	Language
eigval0	Computes the lowest lying eigenvalue of an operator
eig0	Computes the lowest lying eigenvalue and eigenvector of an operator
eigvals_lanczos	Performs an iterative eigenvalue calculation using the Lanczos algorithm
eigs_lanczos	Performs an iterative eigenvalue calculation building eigenvectors using the Lanczos algorithm


matrix	Creates the full matrix representation of an operator on a block
apply	Applies an operator to a state \(\vert w \rangle = O \vert v\rangle\)
norm	Computes the 2-norm of a state
norm1	Computes the 1-norm of a state
norminf	Computes the \(\infty\)-norm of a state
dot	Computes the dot product between two states
inner	Computes an expectation value \(\langle v \vert O \vert v \rangle\)


Spinhalf	Block of a spin \(S=1/2\) type Hilbert space
tJ	Block of a \(t-J\) type Hilbert space
Electron	Block of a Electron type Hilbert space


Op	A local operator acting on several lattice sites
OpSum	Sum of local operators
Coupling	Describes the coupling of a local operator
symmetrize	Symmetrizes an operator with respect to a permutation symmetry group


State	A generic state describing a quantum wave function
ProductState	A product state of local configurations
RandomState	A random state with normal distributed coefficients
fill	Fill a state with a given model state
product	Creates a filled product state
rand	Create a filled random state with normal distributed coefficients
zeros	Create a filled state with all zero entries
zero	Set all coefficients of a given state to zero


Permutation	Permutations of indices or lattice sites
PermutationGroup	A group of permutations
Representation	A (1D) irreducible representation of a finite group


set_verbosity	Sets how much information is printed during computations
say_hello	Prints a nice welcome message with version number
print_version	Prints the plain version number
Logging	Controling what is written to standard output
Timing	Measurng wall time straightforwardly
XDIAG_SHOW	Macro for printing debugging information