Quanty - documentation:tutorials:introduction_to_quanty
https://www.quanty.org/
2026-04-29T06:45:55+00:00Quanty
https://www.quanty.org/
https://www.quanty.org/_media/wiki/dokuwiki.svgtext/html2025-11-20T02:29:40+00:00Anonymous (anonymous@undisclosed.example.com)Eigenstates
https://www.quanty.org/documentation/tutorials/introduction_to_quanty/eigenstates?rev=1763605780&do=diff
Eigenstates
The sixth example discusses eigenstates.
-- Using operators and wavefunctions as explained in
-- the Operators and Wavefunctions example
-- and being able to multiply them to get
-- expectation values we can continue and look
-- at eigenstates of operators
-- define the basis
-- For a p-shell we would like the have 6
-- spinorbitals, with the quantum numbers
-- spin up ml=-1,ml=0,ml=1 and
-- spin down with ,ml=-1, ml=0, ml=1
NF=6
NB=0
IndexDn={0,2,4}
IndexUp={1,3,5}
-- …text/html2025-11-20T02:29:39+00:00Anonymous (anonymous@undisclosed.example.com)Expectation values
https://www.quanty.org/documentation/tutorials/introduction_to_quanty/expectation_values?rev=1763605779&do=diff
Expectation values
The fifth example discusses expectation values.
-- Using operators and wavefunctions as explained in
-- the Operators and Wavefunctions example we can do
-- simple calculations of expectation values
-- Define the basis:
-- For a p-shell we would like the have 6
-- spinorbitals, with the quantum numbers
-- spin up ml=-1,ml=0,ml=1 and
-- spin down with ml=-1, ml=0, ml=1
NF=6
NB=0
IndexDn={0,2,4}
IndexUp={1,3,5}
-- Define 6 one electron wave functions
psi0=NewWavefuncti…text/html2025-11-20T02:29:39+00:00Anonymous (anonymous@undisclosed.example.com)Operators
https://www.quanty.org/documentation/tutorials/introduction_to_quanty/operators_1?rev=1763605779&do=diff
Operators
The second example creates several operators using creation and annihilation operators
-- A basis consists of:
-- a number of Fermionic modes or spin-orbitals
NF=6
-- a number of Bosonic modes (phonon modes, ...)
NB=0
-- Once we have a basis we can define operators.
-- Operators are defined in second quantization.
-- We thus need creation and annihilation operators.
-- Operators are created with the function
-- "NewOperator". This function takes as a first
-- argument the type of…text/html2025-11-20T02:29:39+00:00Anonymous (anonymous@undisclosed.example.com)Operators continued
https://www.quanty.org/documentation/tutorials/introduction_to_quanty/operators_2?rev=1763605779&do=diff
Operators continued
The third examples shows several standard operators acting on a $p$-shell.
-- A basis consists of:
-- a number of Fermionic modes or spin-orbitals
NF=6;
-- a number of Bosonic modes (phonon modes, ...)
NB=0;
-- an index relating the spinorbitals to quantum
-- numbers we assign to them. For a p-shell we would
-- like the have 6 spinorbitals with the quantum
-- numbers spin up ml=-1,ml=0,ml=1 and spin down
-- with ml=-1, ml=0, ml=1
IndexDn={0,2,4};
IndexUp={1,3,5};
--…text/html2025-11-20T02:29:39+00:00Anonymous (anonymous@undisclosed.example.com)Orbitals
https://www.quanty.org/documentation/tutorials/introduction_to_quanty/orbitals?rev=1763605779&do=diff
Orbitals
The first example defines a basis. Note that this example does not produce output.
-- Although Quanty is a many body code,
-- the basis set is defined by one particle
-- orbitals with spin or sites. These are the
-- "boxes" that either can contain an
-- electron or not.
-- These Fermionic modes (lets call them
-- spin-orbitals) can either be the Wannier
-- functions in a solid, molecular orbitals for a
-- molecule or atomic wave-functions for an atom.
-- We obtain these orbitals…text/html2025-11-20T02:29:39+00:00Anonymous (anonymous@undisclosed.example.com)Introduction to Quanty
https://www.quanty.org/documentation/tutorials/introduction_to_quanty/start?rev=1763605779&do=diff
Introduction to Quanty
This tutorial contains several files stepping through the basic ideas of Quanty when doing many body calculations. It introduces the concepts of one electron orbitals, which represent the one electron wave-functions in which electrons can go. Note that we will use the word orbital, or spin-orbital to represent both atomic orbitals, or lattice sites, or molecular orbitals or any other one electron basis set. Operators are defined in second quantization on these orbitals. No…text/html2025-11-20T02:29:38+00:00Anonymous (anonymous@undisclosed.example.com)Wavefunctions
https://www.quanty.org/documentation/tutorials/introduction_to_quanty/wavefunctions?rev=1763605778&do=diff
Wavefunctions
The fourth example creates wave-functions.
-- We start with the same basis as before
NF=6
NB=0
IndexDn={0,2,4}
IndexUp={1,3,5}
-- We now can create wave functions. For this we
-- need three inputs:
-- (1) The number of Fermions and Bosons
-- (2) A list defining the wavefunctions. The lists
-- consists of a string defining a determinant by
-- its occupation: (1 occupied, 0 empty). One bit
-- for each fermion, 8 bit for a boson (i.e. a
-- boson can have an occupation between …