(changelog)=

# Changelog

## Version 3.2.1

CTHYB version 3.2.1 is a patch release contains an important bugfix
in the two-particle Green function measurement.

We thank all contributors: Hugo U. R. Strand, Nils Wentzell

Find below an itemized list of changes in this release.

### General
* Fix crucial bug in G2 measurement
* Fix nfft_array_t to correctly handle move construction and move assignment
* Fix compilation of G2 measurement
* Update scripts for benchmarks measure_g2 hubbard_atom_2bath

### doc
* Correct link to ubuntu debian triqs page
* Correct Ubuntu Version in install instructions
* Update version in website sidebar

### jenkins
* Always build with G2 Measure ON


## Version 3.2.0

CTHYB version 3.2.0 is a compatibility release
for TRIQS version 3.2.0. This release fixes
several application issues and introduces more
accurate ways of calculating high-frequency moments
of the Self-Energy and Green function from the
impurity density matrix

We thank all contributors: Alexander Hampel, Azin Kazemi-Moridani, Harrison LaBollita, Dylan Simon, Nils Wentzell, weiyiguo9

Find below an itemized list of changes in this release.

### General
* Calculate high freq moments of Sigma and G from density matrix
* Enforce hermiticity of measured density matrix (#162)
* Add Tutorial for high freq moments of self-energy and greens function (#163)
* Add tutorial on cthyb convergence tests (#151)
* Use perturbation order in estimate of auto_corr_time
* Raise test tolerance for slater.py and single_site_bethe.py after 80cbb37
* Synchronize clang-tidy config file with app4triqs
* Rename U_matrix -> U_matrix_slater
* Add github actions badge
* clang-format all source files
* General cleanup

### doc
* Enable autodoc for reference manual
* Don't force 'include-source' in plot directives
* Use Markdown for Readme.md and add line breaks

### fix
* Replace numpy.complex by complex
* Fix small error in block accessor var name
* Fix data type of certain parameters int -> long
* Fix 0+ and beta- symmetrization to use full Gtau statistics


## Version 3.1.1

CTHYB version 3.1.1 is a patch release contains a number of bug fixes.
In particular, we resolve incompatibility with recent numpy versions.

We thank all contributors: Alexander Hampel, Nils Wentzell, weiyiguo9

Find below an itemized list of changes in this release.

### General
* fix: data type of certain parameters int -> long
* fix: failing Py_single_site_bethe test
* Update 3.1 easybuild script with sha256 of release tarball
* Bump version numbers from 3.1.0 to 3.1.1

### Doc
* Fix some import statements in guides

### Numpy
* np.complex is deprecated -> complex instead


## Version 3.1.0

CTHYB version 3.1.0 is a compatibility release
for TRIQS version 3.1.0. This release fixes
several application issues and introduces an
alternate Delta Interface that allows users to provide
the hybridization function and the non-interacting
local Hamiltonian instead of the Weiss-field.

### Delta Interface

The Delta Interface allows the user to provide the hybridization function directly instead of providing G0_iw. 
It can be used by setting delta_interface=True when initializing the solver object. 
When calling the solver, the quadratic part of the local Hamiltonian must be provided with the parameter h_loc0, which is a many body operator like h_int.
The Solver.G0_iw and Solver.Delta_infty objects cannot be accessed while using the Delta Interface. 

We provide a more detailed description of the changes and fixes below.

### General
* Use the latest [app4triqs/3.1.x](https://github.com/TRIQS/app4triqs) skeleton
* Switches documentation to read-the-docs theme
* Add parameter Delta_interface that allows to provide h_loc0 and Delta_tau instead of G0_iw
* Add delta_interface as a construction parameter to switch to alternate solver interface
* Test Delta Interface in kanamori_py test
* Add simple measurements for average_order and auto_corr_time based on Z (sign)
* Adjust cthyb to changes in gf_struct object
* Add backward compatibility layers for old gf_struct type
* Add solver property to check if cthyb has been build with complex support
* Allow to set small off diagonal elements of Delta_infty to 0 (#140)
* Fix sanitizer positive, protect division by zero in trace analysis
* Slightly loosen internal check in impurity trace and improve error message
* Run port_to_triqs3 script for TRIQS mesh and nda changes
* Expose h_loc0 in both interfaces and deprecate Delta_infty
* Run git-clang-format
* Regenerate python bindings

### jenkins
* For OSX builds enable complex Hybridisation and Local Hamiltonian and adjust build names

### doc
* Adding multiplet_analysis_notebook guide to documentation
* Add missing image file logo_flatiron.png

### cmake
* Avoid policy warning for CMP0115

### gh-actions
* Install nfft from wentzell/triqs/nfft
* Fix brew nfft install instructions

We thank all contributors: Alexander Hampel, Jonathan Karp, Dylan Simon, Nils Wentzell


## Version 3.0.0

CTHYB version 3.0.0 is a major release that

* is compatible with TRIQS version 3.0.x
* introduces compatibility with Python 3 (Python 2 is no longer supported)
* brings new documentation for measuring the impurity density matrix in cthyb
* fundamental Green function properties are now enforced to increase accuracy

### Fundamental Green Function Symmetries

We now enforce the fundamental Green function properties `G[iw](i,j) = G[-iw](j,i)*`
and `G[tau](i,j) = G[tau](j,i)*` for both the solver-input S.G0_iw as well as the
solver outputs S.G_tau and S.G_iw. The use of this symmetry is enhancing the
effective accuracy of the solver.
If the input violates the relation a warning will be issued and the input will
be automatically symmetrized. The output will always be symmetrized
in the collect_results section of the G_tau measurement.

### Dependency Management

We are managing the interdependencies of the various library components of triqs now using cmake.
Per default cmake will pull those dependencies from their corresponding
GitHub repositories, build them, and install these components together
with TRIQS, unless they are found in your system.
This behavior can be altered using the additional cmake options

* `-DBuild_Deps="Always"` - Always build dependencies, do not try to find them
* `-DBuild_Deps="Never"` - Never build dependencies, but find them instead

during the configuration step. See also the TRIQS documentation for more detailed instructions.

### Other Changes

* Run port_to_triqs3 script
* Port py files to python3
* Update triqs python module name: pytriqs -> triqs
* fixes issue #93 by passing correctly imag_threshold when checking Hloc (#129)
* Fix comparison in atomic_observables test for python3
* Use std::variant over triqs/utility/variant.hpp
* Documentation build no longer requires triqs to be build with doc
* Bump Version number of app4triqs and triqs to 3.0.0
* Add a section on the Anaconda package to the install page
* h5: Adjust to hdf5 header and module changes in triqs

Thanks to all commit-contributors (in alphabetical order):
Philipp Dumitrescu, Alexander Hampel, Nils Wentzell


## Version 2.2.1

CTHYB Version 2.2.1 makes the application available
through the Anaconda package manager. We adjust
the install pages of the documentation accordingly.
It further introduces two minor fixes.
We provide a more detailed description of the changes below.

### doc

* Add a section on the Anaconda package to the install page

### General

* Correct error in solve params deprecation warning Fix #124
* Remove redundant inclusion of triqs/utility/serialization.hpp


## Version 2.2.0

CTHYB version 2.2.0 is a compatibility release
for TRIQS version 2.2.0. It provides improvements to
the documentation and fixes various compiler warnings.

We provide a more detailed description of the changes below.

### cmake
* Install additional triqs namespace headers provided by cthyb
* Synchronize project structure with app4triqs
* Bump cthyb version to 2.2.0 and adjust triqs version requirement
* Minor adjustments in cmake to restore cmake version 3.0.2 compatibility

### doc
* Update install instructions for nfft
* Install svg files used by tutorials
* Add tutorial for pert order histogram
* Add tutoria for dynamic suscept
* Fix import statements -> static observables (import from atom_diag)

### General
* Use std::vector over triqs::arrays::vector for density containers
* Fix various compiler warnings and deprecation messages
* Consistently use std:: namespace instead of std::c14::
* Remove remainders of separate cpp2py install from modulefile
* Bump cmake version requirement to 3.0.2
* Port cthyb after latest changes to triqs mpi/itertools functionality
* Add measurement O_tau_min_ins

### h5
* Store additional member variables when storing solver object, FIX #115

### packaging
* update package name to triqs_cthyb and conflict with cthyb


## Version 2.1.0

### Contributors

* **Hugo U. R. Strand**, new functionality, two-particle Green's function sampling in imaginary time and frequency, and sampling by operator insertion.
* **Igor Krivenko**, occupation number constraints in the trace, two-particle Green's function sampling with NFFT and mixed basis frequency*(legendre)^2.
* **Lewin Boehnke**, (indirect contribution) through the first mixed basis sampling implementation in an early version of ``cthyb``.
* **Nils Wentzell**, nfft_buf_t, cmake, and install.

### Testers

Manuel Zingl, Daniel Mantadakis, and Jonathan Karp.

### Changes in installation and cmake files

* Headers are now installed to ``${CMAKE_INSTALL_PREFIX}/include/triqs_cthyb``.
* The c++ namespace is now a single namespace called ``triqs_cthyb``.
* The python module is named ``triqs_cthyb``.

### Solver Interface

* The type of gf_struct has changed from a dict to a list of pairs

  ``{ 'up' : [0, 1], 'dn' : [0, 1] }    -->   [ ('up', [0,1]), ('dn', [0,1]) ]``

* measure_g_l has been renamed to measure_G_l
* measure_g_tau has been renamed to measure_G_tau

* Truncation of the local Hilbert space in total density using ``loc_n_min`` and ``loc_n_max``
* Two particle Greens function sampling with a whole set of measurements see ``measure_G2_*``
* Two particle susceptibilities sampling by insertion using `measure_O_tau`
* Tunable parameters for the determinant regularization see `det_*` parameters
* Solver object can be stored and loaded directly to/from h5 archive
* Tail fit functionality is rewritten for the Triqs 2.0 change in how tail coefficients are handled

### Changes in behavior

* ``move_double`` is now enabled by default.
* The sampled single particle Greens function is modified when tail fitting is enabled.
* The ``gf_struct`` should be a list of list of block index and a list of target space indices, e.g.

  ``gf_struct = [['up', [0, 1]], ['down', [0, 1]]]``.

  When passing a dictionary a warning is printed.

### Dependencies

* The NFFT3 library by default, to compile without the library use the cmake flag ``-DMeasureG2=OFF``.