Pyscf

* Added
- k-point symmetry for mean-field methods and MP2
- UCASSCF work with state_average
- make_rdm12s for MCSCF state_average
- Staggered mesh method for k-point restricted periodic MP2 energy
- PBC-X2C1E DFT methods in spin-orbital basis
- Adds make_rdm2 to RHF and UHF
- Auto-generate frozen-core orbitals
- Atomic chemical core configuration
- Various MGGA functionalities (Gradients, Hessian, TDDFT, etc.)
- Mcfun (multi-collinear functional) and relevant GKS, DKS, X2C-DFT, TDDFT methods for molecules
- Supports to aarch64 architecture
- Atomic spherically averaged DFT and add HFS ground-state configurations
- RPA, URPA
- UCCSD with density fitting
- X2C for GHF/GKS on spin-orbital basis (make identical to X2C-SCF with j-adapted basis)
- Gamma-point periodic EA/IP-ADC
- K-point periodic EA/IP-ADC
- CVS-IP-ADC
* Improved
- DFT numerical integral module with better integral screening
- Aligns E(HF) of KRCCSD with other CCSD classes, and CISD, MP2 classes
- Adjustable screening value for eval_ao function
- MCSCF convergence for small systems
- Renormalized perturbative triples correction in CCSD
- Optimises UCCSD 1DM
- Linear dependency handled for IAOs
- vhf prescreeening efficiency
- Lattice sum ranges in PBC AO-value evaluation
- Various cutoffs in PBC integrals for exceptional cells
- Handles 1e system for KS methods
- Try to use original axes when creating Mole object if pointgroup is inputed
- More symmetry information of MCSCF active space dumped
- SA-CASSCF nuc grad API reform
- Upgrade cint library to v5
- Accelerating SGX module
- rsdf, gdf, aft, mdf, ft_ao, rsjk modules refactored and their performance are optimized
- The return status of HF statbility checks
- GDF 3-index integral tensor loader to support tensor sliced from disk
* Fixed
- Dynamic level shift for UHF
- gamma-point TDDFT by adding response fn
- Initial guess issue for uhf custom Hamiltonian
- Projecting the dm to a larger basis set in PBC systems using from_chk() and init_guess
- Ensure deterministic result from pyscf.lib.einsum
- Symmetry detection bugs and C2v orientation for planar molecules
- State-average CASSCF 1RDM for orbital canonicalization
- wfnsym for state_average CASSCF
- Concatenating two Molecule objects with ecp
- cisd.tn_addrs_signs for impossible excitations
- KMP2 takes KHF with precomputed GDF integrals
- Huckel guess with mol.cart=True
- UCCSD 2RDM without frozen

* Update libcint to 4.4.6
* Update openblas version in pip wheels

- The Python-2 support was dropped. The minimal Python version needs 3.6

- New features, bugfixes, improvements in this release were contributed by: Abdelrahman Ahmed; Alexander Sokolov; Bryan Lau; Eric Hermes; Garnet Chan; Henrik R. Larsson; Hongzhou Ye; Huanchen Zhai; Hung Q. Pham; James E. T. Smith; Jan Hermann; Janus Juul Eriksen; Kevin Focke; Kevin Gasperich; Lucas K. Wagner; Marc Barbry; Mark Williamson; Matthew Chan; Matthew R. Hermes; Matthew Treinish; Matthias Degroote; Max Nusspickel; Maximilian Scheurer; Muhammad Firmansyah Kasim; Nikolay Bogdanov; Oliver Backhouse; Peter Pinski; Qiming Sun; Samragni Banerjee; Sandeep Sharma; Shiv Upadhyay; Simon Ewing; Susi Lehtola; Terrence Stahl; Tianyu Zhu; Timothy Berkelbach; Verena A. Neufeld; Xiao Wang; Xing Zhang; Yang Gao; Yixiao Chen; Zhenyu Zhu; Zhihao Cui

- Online documentation was greatly improved in PySCF 2.0 with help from: Alexander Sokolov; Chong Sun; Garnet Chan; Hongzhou Ye; Huanchen Zhai; James E. T. Smith; Jan Hermann; Janus Juul Eriksen; Kyle Bystrom; Oliver Backhouse; Peter Pinski; Qiming Sun; Samragni Banerjee; Sebastian Ehlert; Seunghoon Lee; Susi Lehtola; Tianyu Zhu; Timothy Berkelbach; Verena A. Neufeld; Xing Zhang; Xubo Wang; Yang Gao; Zhihao Cui

Dr. Susi Lehtola offered major help to review all pages throughout the
entire online documentation project.

- Release pipeline and collaboration pipeline were updated with contributions from: Mark Williamson; Qiming Sun; Xing Zhang

Dr. Mark Williamson offered major help to set up the pipeline using Github Actions

* Added
- Basis selector '' to load basis from a file
- Native version of DF-MP2 for RHF and UHF references
- Cholesky orbitals as the initial guess for iterative orbital localization.
- FNOCCSD
- SCS-DF-MP2
- Relaxed RHF-DF-MP2 density
- int1e_grids function to compute Coulomb integrals for a list of grids
- GDF-KMP2
- Custom Hamiltonian for UHF
- Natural Orbitals for DFCASCI and DFCASSCF with approximate CI solvers
- slow and fast QCISD and QCISD(T) for restricted refs

* Improved
- Pacakge layout, static checks, and code releasement pipeline.
Certain features were removed from core modules, including: cornell_shci, dftd3, dmrgscf, doci, fciqmcscf, icmpspt, mbd, Molpro2Pyscf, mpicc, nao, semiempirical, shciscf, tblis, prop/efg, prop/esr, prop/freq, prop/gtensor, prop/hfc, prop/magnetizability, prop/nmr, prop/nsr, prop/polarizability, prop/rotational_gtensor, prop/ssc, prop/zfs
- Compatibility improvements for Python 3.6 and newer
- Compatibility improvements for h5py 3.0 and newer
- Online documentation (https://pyscf.org/user.html)
- Upgrade Libxc to 5.1.7
- FCIDUMP interface to include ECP scalar contribution
- DMRG interface
- Ghost atoms in IAO/IBO
- PBC-GDF auxiliary basis treatment with nonzero drop_eta
- pivoted Cholesky factorization
- Support high angular momentum in GTO basis (up to l=15)
- Make Exact FF GW root finding more robust, reduce eta
- cubegen for arbitrary unit cells
- Range of lattice sum for non-orthogonal lattice
- krkspu
- Number of calls to gc.collect()

* Fixed
- PBC-GDF and PBC-MDF when computing RSH functionals
- The edge case for zero beta electrons in SCF
- Atomic initial guess if multiple elements have ecp
- The ordering of unique points in kpts.unique function
- J matrix of AFTDF
- kuccsd rdm1
- GDF int2c2e integrals for non-symmetric range of lattice sum
- Complex-valued symm. adapted basis
- NEVPT2 for multistate CI wave function

PySCF-2 alpha version created by release pipeline. Features are the same to those released in v1.7.6

* Added
- KMP2 2-particle density matrix
- PBC J, K matrices module rsjk (RangeSeparationJKBuilder)
- ADC (RADC, UADC, DFADC)
- Eigenvector analyzer for IP and EA, RADC and UADC
- Analytical nuclear gradients for state-average CASSCF
- Support SO3 symmetry
- ECP-SOC for GHF/GKS
- density fitting GMP2
- G0W0 approximations (analytic continuation, contour deformation)
- Auxiliary second-order Green's function perturbation theory (agf2)
- Smearing for molecules
- Visscher small component correction approximation for DHF
* Improved
- Threading safety in Mole temporary context
- Basis parser to support arithmetic expressions in basis data
- dmrgci interface refactored
- MP2 gradients performance
- Interface of polariazable embedding with integral batching
- Electron-phonon Hamiltonian module refactored
- Remove memorization of Ewald parameters.
- molden dumper refactored
* Fixed
- stack overflow in ecp integral code
- SCAN functional crashing problem
- Ghost atoms for IAOs/IBOs
- Fix fractional occupations for case of zero beta electrons
- mcscf project_init_guess
- Symmetry verification bug when deducting subgroup
- Mole.set_geom_ bug
- GDF with non-zero drop_eta (for diffused auxiliary basis)
- Paddings in KMP2 when remove_linear_dep_ is applied
- SC-NEVPT2 Sijr Srsi