Pyscf

* Bugfix
- CISD output message for multiple roots
- Uhf hessian function in the second order SCF solver
- Integer overflow in npdot
- Module import error in pbc second order SCF solver
- Update makefile due to the bugfix in libcint library

New features:

* Spin-free X2C Hamiltonian for PBC calculation
* Overlap of two CI wavefunctions over different orbital bases
* EOM-CCSD for user guess, Koopmans' excitations, etc
* Approximate EOM-CCSD (MBPT2 ground state and partitioned EOM Hbar)
* AVAS method for constructing CASSCF active space
* Molpro XML file reader and interface to read Molpro orbitals
* Supports for 1D, 2D PBC systems
* Quantum chemistry ECP for crystalline system
* AO-driven CCSD
* UCCSD
* CI coefficients transformation for one-particle basis rotation
* CIAH second order SCF solver for PBC KRHF and KUHF methods
* CISD and CISD 1, 2-particle density matrices
* Selected-CI and Selected-CI 1, 2-particle density matrices
* Smearing for PBC mean-field calculation
* Density fitting (with Gaussian as auxiliary basis) for crystalline systems

Improvements:

* Performance of CCSD(T)
* The default kpts mesh (to always include gamma point)
* Treatment of auxiliary basis linear dependence in PBC DF/MDF module
* Atomic grids in PBC DFT calculation
* Cutoff radius in real space lattice summation for better accuracy
* EOM-EE-RCCSD and EOM-EE-UCCSD performance
* Memory usage of the non-symmetric Davidson solver in EOM-CCSD
* Integral transformation for PBC 2-electron integrals
* CASSCF state-average interface to handle sub-solvers of different spins
* Numerical stability for Davidson diagonalization solver
* Numerical stability of FCI contraction function under multi-threading environment
* Performance of FCI 2-electron contraction function with point group symmetry

* Bugfix
- PBC 2e integrals for wrap-around k-points
- CI coefficients in GAMESS WFN format
- Input parser for Gaussian nuclear model
- Density fitting outcore module for user input auxiliary basis

- Bugfix
- GTO normalization in molden file
- multi-threading dgemm

- Added
- transition metal BFD basis
- script to fix dylib library dependence for Mac
- Bugfix
- active space 1pdm in mc chkfile if natural orbitals are required
- dmrg example
- state-average dmrgci interface
- analytic GTO-PW integral
- for population analysis when ecp is presented.
- for mcscf state-specific function to support ground state as the target state
- get_coulG round-off bug
- unit cell size estimation for non-orth crystals
- lib.norm function for complex vector

- Added
- State average CASSCF helper function for mixed spin/spatial-symmetry FCI solvers
- Example for transition dipole momentum
- U-CCSD (based on spin-orbital formulation)
- IP/EA/EE-EOM-CCSD
- Function to dump CASSCF canonical orbitals in molden format
- Analytical Fourier transformation for AO and AO product
- Co-iterative augmented hessian (CIAH) orbital optimizer
- Optimized einsum function using numpy.tensordot function
- Burkatzi-Filippi-Dolg pseudo potential
- FCI solver to support integrals which do not have 8-fold symmetry
- Dual interface to call pyFFTW or numpy.fft
- Maximum overlap method (MOM) method for SCF method
- Improved
- Memory usage for MDF method (molecular and PBC systems)
- PBC AO value evaluation performance
- Orbitals space symmetrization
- CASSCF subspace (core, active, external) symmetrization
- Created X2C object to hold X2C functions and parameters
- Boys, Edmiston, Pipek-Mezey Localization with general CIAH optimizer
- PBC integrals to handle ghost atom in PBC calculation
- Asynchronized IO to overlap integration and IO for ao2mo integral transformation
- SCF gradients to eliminate the symmetry forbidden matrix elements
- Fixing orbital ordering for degenerated SCF orbitals
- Efficiency of transpose_sum function
- FCIDUMP output format
- Bugfix
- CASSCF/QMMM interface for the missing term in nuclear repulsion
- Screening small density for MGGA functionals
- Molden interface to handle symmetry broken orbitals
- MP2 density matrix to include HF DM