```{only} html
<span data-index="remove-from-meili" hidden></span>
```

(sec:appendix.changelog)=
# Detailed change log

## Changes ORCA 6.1

### New Features

#### Startup, Guess, LeanSCF
- BUPO algorithm.
- Significant memory improvements in Startup, Guess and LeanSCF.

#### DFT
- Added B3LYP-3c method.
- Extension of HF-3c, PBEh-3c, B97-3c, and B3LYP-3c for elements Fr-Pu (using original D3 parameters)
  and r2SCAN-3c up to Lr (Z=103).
- ADFT (Energies, gradient, response, TD-DFT, NOT GIAO, NOT analytic Hessian).
- RPA correlation energy a la Andreas Görling (no gradient, density or response yet; NumGrad, NumFreq).
- Simple input keyword for B2NC-PLYP double-hybrid.
- Added various simple input `LibXC(method)` keywords for DFT functionals, e.g. TASK-LDA, revTM, HSE06, GAS22.

#### Native xTB Methods
- Native implementation of GFN1-xTB with energy & gradient.
- Native implementation of GFN2-xTB with energy & gradient.
- Native xTB methods can use the ORCA SCF and plotting infrastructure.
  Plotting of molecular orbitals, densities, and fractional occupation densities (FODs) can be done with `orca_plot`.
- Spin-polarized methods spGFN1-xTB and spGFN2-xTB.
- JSON parameter file for custom parameterizations of GFN1- and GFN2-xTB.
- Native implementation of the ALPB solvation model for xTB methods.

#### Solvation
- Analytical DRACO gradient.

#### SCF Linear Response
- Analytical Raman intensities: HF, DFT up to meta-GGAs, RIJ and COSX,
  implicit solvation, external point charges. Significantly faster than NumFreq.
- Static dip/dip/dip hyperpolarizability: same range of validity as Raman intensities.

#### Orbital localization
- IAO-based valence virtual orbital localization methods (`PMVVO`, `LIVVO`).
- Different options for IAO minimal basis.
- Optionally use a different localization method for virtual MOs via `%loc`.
- LMO plotting enabled in input file.

#### Optimization
- New redesigned L-OPT - an L-BFGS optimizer for geometry optimization of large systems -
  more efficient than before.
- !RIGIDBODYOPT for optimization of structures/fragments as rigid bodies.
- Replaced frozen coordinates (`$` syntax) with X/Y/Z Cartesian constraints.

#### NEB
- More robust initial path generation using S-IDPP.

#### Excited states
- Core ionization/excitation energies using UHF IP-EOM-CCSD and STEOM-CCSD.
- Multi-core calculations for RHF/UHF Canonical and BT-PNO IP-EOM and STEOM-CCSD
  (DLPNO for now can only do 1 core at the time).

#### GS-ROCIS:
- Spin-orbit coupling is now implemented.

#### DeltaSCF
- Generalized mode following method.
- Freeze-and-release method.

#### MDCI
- Add `DT_in_Triples` correction for RHF reference with a check to skip for small $F_{ia}$.

#### AutoCI
- Third order NEVPT (NEVPT3).
- Fourth order NEVPT restricted to singles and double excitation (NEVPT4(SD)).
- Export single-reference CI/CC 2RDM to JSON.
- UHF CCSDTQ.

#### AutoCI Response
- RHF CCSD dipole-dipole polarizability, with and without orbital relaxation.
- RHF and UHF CCSD(T) dipole-dipole polarizability, with and without orbital relaxation.
- RHF and UHF CCSD quadrupole-quadrupole polarizability, with and without orbital relaxation.
- RHF and UHF CCSD(T) quadrupole-quadrupole polarizability, with and without orbital relaxation.
- RHF and UHF GIAO-CCSD NMR shielding, with and without orbital relaxation.
- RHF and UHF GIAO-CCSD(T) NMR shielding, with and without orbital relaxtion.
- UHF GIAO-CCSD EPR g-Tensor, with and without orbital relaxation.
- UHF GIAO-CCSD(T) EPR g-Tensor, with and without orbital relaxation.

#### CASSCF Module
- ICE NEVPT2 using the full ranked formulation (ICE-FR-NEVPT2).
- Multiconfiguration pair density functional theory (MCPDFT)
  - with translated functionals tLDA, tPBE, and tPBE0
  - and with complex translated functionals ctLDA, ctPBE, and ctPBE0
- Long-range CASSCF short-range DFT (srDFT)
  - with short-range functionals sr-LDA, sr-PBE, and sr-PBE0
  - short-range pair density functionals: sr-ctLDA, sr-ctPBE, and sr-ctPBE0
  - robust RI approximation for range-separated integrals used for RI-J and RI integral transformation
- Effective Hamiltonian CI-DFT approach for excited states with MCPDFT and srDFT.

#### CASSCF Linear Response
- New options to toggle the orbital response, solution locking, and Olsen preconditioner in `%casresp` block.
- Nuclear-orbit perturbation implemented (allows for calculation of `Aorb` contribution to EPR A-tensor).
- Block preconditioner to reduce the number of iterations and computation time.

#### MR methods
- RASCI / ORMAS module.

#### MCRPA module
- Block preconditioner to reduce the number of iterations and computation time.
- Orbital response can be turned off. This corresponds to a CAS-CI calculation.

#### Multiscale
- Automated generation of QM and active regions.
- MM-only calculations can now make use of active atoms keyword.
- Added fast Simple_Eq option for topology preparation of QM/QM2 runs.

#### MD Module
- Langevin thermostats are now available (random force and drag term can be switched on separately).
- Constraints: Can now automatically constraint all bonds/angles involving a certain element (e.g. H).
- Restraints: Can now define custom restraint function by arbitrary mathematical expression.
- Added new "Radius of Gyration" Colvar (can restrain the system to spherical shape, e.g. a drop).
- Metadynamics: Can now define custom Colvars by arbitrary mathematical expression.
- Can now modify atom masses during MD simulation.
- Many more options for velocity initialization (e.g. let certain molecules rotate or translate).
- "Reference trajectory" feature to re-compute snapshots from an existing trajectory.
  Can also compute work along a path.
- Wavefunction extrapolation (ASPC) to reduce number of required SCF cycles.
- Possibility to apply additional arbitrary forces to atoms (e.g. for experiments with own bias potentials).

#### Thermochemistry
- Diagonal Born-Oppenheimer correction.
- Spin orbit coupling correction to the total energy via approximate 2 components.

#### NMR
- Enabled shielding calculations with X2C and the finite nucleus model.

#### Energy Decomposition and Wavefunction Analysis
- Atomic decomposition of London dispersion (ADLD).
- Atomic decomposition of exchange energy (ADEX).
- LED for covalent bonds (COVALED).
- New implementation of ETS-NOCV.
- Enabled LED with X2C Hamiltonian.
- RIJCOSX can now be used for DLPNO-CCSD(T)-LED with non-hybrid DFT as reference wavefunction.

#### AILFT
- Extended Spaces AILFT (ESAILFT).

#### Magnetic Relaxation Rates
- Orbach and Raman II pathways (`orca_magrelax`).

#### RESP/CHELPG charges
- RESP charges with parabolic and hyperbolic constraints.
- Can now define sets of equivalent atoms which will have identical charges.

#### ANISO
- Update of the ANISO interface in ORCA to support MRCI.

#### Basis Sets
- 6-31G* for Ga-Kr.
- CRENBL basis and CRENBL-ECP.
- New Jensen basis sets: pcX-n, aug-pcX-n, pcH-n, aug-pcH-n (n = 1,2,3,4).
- Reimplemented def-SVP, def-SV(P), def-TZVP, def-TZVPP (H-Lr).
- Extended def2-mSVP, def2-mTZVP, and MINIX up to Lr.
- Extended def2/J option for elements Fr-Lr.
- Extended def2/JK option for elements La-Lu, Fr-Lr.

#### Property File
- Added SCF and job timings.
- Added DBOC, gCP, and SOC energy contributions.
- Added ESD fluorescence rates.
- Easier conversion to JSON via `%output JSONPropFile=true`.

#### `orca_2json`
- Compute and export AO-basis Fock matrix as well as separate J, K, XC, and CPCM terms.
- Convert JSON property files back to native ORCA format
  (with limited support for 6.0 files).
- Added SOC integrals.

#### Miscellaneous
- Geometry input from GBW files.
- TransInvar for Numerical Hessian.
- Thermochemistry Compound script for the HEAT protocol by Stanton et al.


### Improvements

#### TDDFT
- Improved `FollowIRoot` stability.
- TD-DFT amplitudes now stored in GBW file.
- TD-DFT calculations are restartable from a GBW file.

#### GOAT
- GOAT-COARSE option for automated coarse-grained conformational search.
- GOAT-DIVERSITY for a conformational search looking for maximal structure diversity.

#### DOCKER/SOLVATOR
- Faster by about 100x, with many improvements and updates.
- DOCKER can now do the search only on limited region of the host by defining a center and extent of the search.

#### AutoCI
- Significantly improved scaling and runtime performance (speed, memory and disk space requirements)
  for AUTOCI-MP5 energy.
- Improved RHF CCSD(T) 2RDM performance.
- UHF CCSD(T) gradient accuracy (disconnected 3rd and 4th order contributions were missing, now corrected).
- Response: UHF CCSD Polarizability, solver performance improved significantly.
- Response: switched to sequential handling of response equations
  (less disk requirements for large calculations, compared to solving all perturbations together).
- Printing improvements.

#### CASSCF
- Aborts at beginning if CASSCF is requested with a dispersion correction.
- General warnings added about number of roots when CASSCF LR is run.
- TRAH submodule: final active orbitals are the same and sorted the same as in other CAS convergers.

#### CASSCF Linear Response
- More reasonable threshold for LR equation solution is determined by default.
- Uses solution locking by default.
- Checking at start that there are response parameters with which to perform LR calculation.

#### OpenCOSMO-RS
- Gas-phase orbitals can be used for the calculations in solution.

#### MD Module
- Added many more warnings (e.g. when two atoms come too close during a simulation).
- Added many different options how to handle non-converged SCF.
- Random velocity initialization now yields a zero angular momentum by default (i.e. system will not rotate).

#### Thermochemistry
- Extended max number of allowed temperatures and pressures to 100.

#### DKH
- Only compute the shell-pair data once.

#### X2C
- Skip grid setup if not needed.

#### OPS refactor
- Important: keywords to request multipolar spectrum has been simplified.
  Some Orca 6.0 keywords are no longer available.

#### QDPT module
- g-tensor `g(OZ/SOC)` now includes QED correction factor.
- g-tensor `ggauge` and `g(OZ/SOC)` can now be printed in molecular frame (with higher print level associated with QDPT).
- Enabled sum-over-states for CAS and MRCI.
- Reduced memory usage for SSC ZFS calculation.

#### Property File
- All properties and components now documented in the manual.
- Some components are now stored optionally/conditionally.
- Disable property file storage by default for `!MM` and `!GFN-FF`
  (in addition to `!GOAT` and `!MD-L-Opt`).
- Common component structure for energy properties:.
  `SCF_Energy`, `AutoCI_Energies`,
  `CAS_SCF_Energies`, `CAS_DCD_Energies`, `CAS_PT2_Energies`,
  `CIS_Energies`, `MDCI_Energies`, `MP2_Energies`.
- `Calculation_info`: Removed (unassigned) `NumOfFCElectrons` and `NumOfCorrElectrons`;
  moved "final single point energy" to geometry-dependent `Single_Point_Data` property.
- Stored MR-AUTOCI energies.
- Method-specific population analyses.
- Method- and state-specific nuclear gradient, removed `ATNO` component.
- `G_Tensor`: also store `g_PSO`, `g_DSO`, `Delta_g` components.
- `A_Tensor`, `EFG_Tensor`: removed `activeNucs`.

#### Miscellaneous
- Default MaxCore increased to 4GB.
- UCO/UNO generation performance improvement.
- Allowed simple input of DSD-PBEP86, DSD-BLYP and DSD-PBEB95 with D4.
- DeltaSCF: improved preconditioner with SOSCF.
- NEB: fragment preparation.
- Various improvements in `orca_mapspc`.
- Various fixes, additions, and improvements in Compound.


### Fixed

#### TDDFT
- DCORR should now respect MaxCore and abort neatly if it is insufficient.
- Wrong JSON output of TDDFT/TDA amplitudes and TDA excitation energy.
- Fix bug of TDDFT calculations with semiempirical methods.
- Fixed GS energy storage when SOC is enabled.

#### MDCI
- Respect MaxCore when building CPCM containers for PTE(S) and PTES.
- UHF-based CCSD producing wrong results with `!CONV`.
- Race condition resulting in wrong results in parallel for PTE(S) and PTES.
- S-diagnostic for canonical RHF and UHF.
- Fixed integral transformation problems.
- Fixed problems with Brückner and orbital optimized UHF CCD.
- Estimate required memory in RI/DLPNO exchange-like
  integral half-transformation to prevent OOM death.
- Stop calculation if MDCI equations do not converge (same as for SCF).
- Rare pair-pair integral crash.

#### MP2
- MP2 with ANOs works now.

#### CASSCF/NEVPT2
- FIX: Custom `EDIAG` failed due to wrong unit conversion - the input energies should now be in Eh.
- FIX: Increased number of states for custom EDIAG (hard-wired).
- FIX: Abort if an unsupported CI solver is requested with TRAH.
- CABSSinglesCorrection is now default in a DLPNO-F12-NEVPT2 (DoCABSSingles=1).
- FIX: MaxIter not properly passed in DLPNO-NEVPT2.
- FIX: QD-NEVPT2 densities not properly used in property calculations.
- FIX: NEVPT2 property calculations now track ground state changes.

#### MCRPA module
- Removed runtime bottleneck in final CI wave function printing
  that became an issue for many roots and long CI expansions.

#### QDPT Module
- `ggauge` was still using `CenterOfNucCharge` for magnetic gauge origin;
  now uses globally set magnetic origin.
- Other g-tensor fixes to first-order contributions (now consistent with `orca_prop`).
- Issues with QDPT transition densities from ROCIS.

#### CASSCF QDPT properties
- Corrected indexing of transition densities and ground-state spin densities.
   - Affected properties: EFG tensor, RHO, first-order g-tensor contributions, SOS properties.
- Memory issue in SSC calculation.

#### QDPT Module Sum-over-states
- Runs now if g-tensor is requested with `DoSOS true`
  (before, A-tensor had to also be requested).
- SOS g-tensor now gives full agreement with CAS LR (without orbital response)
  when all roots are included in CAS/MRCI QDPT calculation.
- Corrected general retrieval of transition spin densities.
   - NOTE: SOS is thus only available for methods where transition spin densities are available
           (now: MRCI, CASSCF, CASSCF+NEVPT2, CASSCF+Custom diagonal energies)

#### MD Module
- External forces on Colvars are now properly computed
  (relevant e.g. for thermodynamic integration).
- Many bugfixes (e.g. for the "too many arguments" bug).
- Gradients were not computed for CIS and broken symmetry.

#### Solvation
- Various options for CPCM: analytic, numeric RI, multipole.
- DRACO keyword not ignored anymore for QM/MM calculations.
- Fix crash for calculations requesting CPCM (bare CPCM / SMD / openCOSMO-RS)
  if the atomic number of an element in the solute is >= 106.

#### Dispersion
- Additional `!ATM` alias for the Axilrod-Teller-Muto type
  three-body-dispersion treatment available via `!ABC`.

#### EPR
- Crash in `orca_euler` when number of EFG and HFC nuclei differ.

#### NMR
- ZORA NMR now automatically triggers numeric GIAO 1-el integrals, as in ORCA 5.
- Fixed parallel race condition in DLU-X2C NMR leading to wrong results.
- `Tau=Dobson` default now correctly applied to GIAO calculations.
- Abort for NMR couplings with ZORA (not implemented).
- Fixed hanging of DSO coupling term with X2C when shieldings are also requested.
- Fixed GIAO XC integration for B97-3c with XCFun.

#### Optimization
- The "big step" fallback should also work if only Cartesian constraints are used.
- Switch off group parallelization if `(Re)CalcHess` is needed.

#### Relaxed Surface Scan
- Now it allows negative dihedrals on input, improved error report.

#### DOCKER/SOLVATOR
- Issue when swarming the best structures.
- Fix the chirality of the moment of inertia to avoid creating stereoisomers.
- Wall potential issue when some atoms are very far from the centroid.
- Small fix for solvent dimensions.

#### Hessian
- Fix for NearIR in `PrintThermoChem` if `InHessName` is different from `BaseName.hess`.
- Fixed issue when writing the IR spectrum multiple times.

#### X2C
- Disable general contraction for decontracted ANO basis, which led to slowdown.
- CIS/TDDFT gradients with X2C were not picture-change corrected.

#### Thermochemistry
- D(inf)h point group was not correctly parsed for rotational entropy contribution.

#### Inertia Tensor
- VPT2 and PAF : Fixed Inertia Tensor calculation.

#### Rotational Constants
- Minor fixed on unit transformation constants.

#### Basis sets
- All of SHARK and ORCA now works up to L=10 (except Hessian).

#### SCF Linear Response
- Fixed issue with initialization of BHP22 solver.

#### Windows
- Windows-specific crash in `orca_mapspc` fixed.
- Parallel subcalculations in NumCalc (NEB, NumGrad, VPT2, ...) now also available on Windows

#### Property File
- Re-implemented JSON output via the N. Lohmann library (version 3.11.3)
  to guarantee valid syntax.
- Alleviated memory and timing overhead.
- Respect `%output PropFile=false`/`!NoPropFile` keywords.
- `Quadrupole_Moment`: `EXZ` and `NUCXZ` components held YZ value instead.
- Hessian was stored incorrectly in XTB jobs.
- CIS/TDDFT gradient root was stored incorrectly.
- `Chemical_Shift` components `SPSO`, `SDSO`, and `saniso` were not stored.
- `Calculation_Info` was not stored in some calculations.
- MM, XTB, and ExtOpt jobs now store the geometry and final energy.
- Geometry in JSON output was missing ghost, fragment, and ECP data.

#### Miscellaneous
- Crash in SOSCF.
- Cleanup leftover files of stability analysis with DFT.
- Atomic fitting density not working with partial general contraction.
- Occasional crash in integral loop.
- Missing PDB file output in QM/MM NEB.
- Prevent crash when reading the nodefile in GOAT, NumFreq, etc.
- Bug in one-sided numerical gradient `TransInvar=true`.
- Restored functionality of `!AIM`.
- Removed leftover temporary files in AUTOCI.
- Restore original irreps if the prediagonalization is skipped in SCF.
- Crash in Hessian for systems with no beta electrons.
- Restored functionality of the `!DoEQ` keyword.
- Opt+NumFreq or Opt+IRC jobs with `!ExtOpt` were stopping after the optimization.
- Print headers for all monitored internals in IRC.
- Fixed HFLD when no pairs are identified.
- Removed RIJCOSX-only restriction for wB97X-3c.
- CP-SCF now aborts if unconverged.
- RI Trafo in CIPSI works now.
- Fixed memory leaks in AO-MP2, QDPT, `orca_2json`, ECPs, ROCIS, LFT, and others.
- Spectrum intensity printing and decomposition in `orca_mapspc` for cases beyond the dipole approximation.
- `orca_vpot`: Fixed ESP calculation when contraction change.


### Removed

#### CASSCF/NEVPT2
- QD-NEVPT2 with Cloiszeaux Hamiltonian (QDType=QD_Cloiszeaux).
- Some options for the handling of reduced density matrices in NEVPT2  (D4Step=core, D4Step=D4PT).

#### MCRPA module
- If the eigenvalue equations fail to converge,
  the connection to CASSCF wave function instability is not mentioned anymore.
  The manual section has also been removed.


## Changes ORCA 6.0.1

### Fixed

#### DFT
  - Crash when XCFun functional was overwritten with LibXC.
  - Hessian fixed for DFT GGA, NoRI, RKS.
  - VV10 Hessian is blocked even if invoked with `CALC_HESS=TRUE` and similar.
  - Wrong orbitals for non-self-consistent DFT-NL calculations (wB97M-V, wB97X-V, B97M-V).
  - `X_WR2SCAN`:
    - Exchange can now be specified individually in the `%method` block.
    - Fixed crashes when second derivatives are requested.
    - TRAH is now disabled per default when using `X_WR2SCAN`.
    - If second derivatives are requested, will now automatically switch to numerical second derivatives.
    - Added appropriate warnings for the above changes.
  - Fixed PBEh-3c gCP parameters for Krypton and Lithium to be consistent with Grimme's stand-alone.
  - gCP is now fixed (and extended) for r2SCAN-3c up to Z=103.
  - Remove restriction to COSX for wB97X-3c .
#### TD-DFT
  - Ground state gradient for TDDFT calculations with `sgradlist` was wrong.
  - `DCORR` 2/3 with `DoSCS` giving wrong results in parallel.
  - (D)-Correction not available for full TDDFT.
  - Fix for memory estimates for Hessian/TDDFT when running without COSX.
  - `FollowIRoot` was not supposed to do anything if the overlap was to small, was still updating.
  - Fixed interface to `BHP22` solver in CIS.
#### MP2
  - Crash in conventional U-MP2.
  - Parallel crash in RI-MP2 density.
  - Crash in (RI-)MP2 gradient with SMD.
  - Crash in (RI-)MP2 density with PGC and RIJK.
  - MP2+CPCM gradient was wrong.
  - Crash in NearIR + B2PLYP.
  - Bug with MP2 gradient in property file.
#### MDCI
  - SemiCore was not applied correctly if ECP is present.
  - ECP-related crashes.
  - Fixed redundant integral generation for specific problems.
  - Restored old CITrafos to address reported performance issues.
  - Added missing 4th-order doubles term in (T) for RKS reference (already present in UKS-(T), RKS-DLPNO-(T), and UKS-DLPNO-(T) and zero for RHF/UHF reference).
  - UHF CIS/STEOM calculation with `UseCISUpdate` is set to `false`.
  - RHF STEOM: TD-DFT initial guess.
#### AutoCI
  - Fixed large stack allocation, e.g., in MRCC.
  - Fixed runtime behavior for `!Moread Noiter` (falsely reporting "not converged").
  - Fixed `!UseSym` falsely aborting.
  - AutoCI gradients: abort at start of a calculation when RI is requested instead of after coupled cluster iterations.
#### CASSCF/NEVPT2/QD-NEVPT2
  - Issue running LR over SA-CASSCF solution.
  - Incorrect setting of gauge origin in CASSCF QDPT led to misleading output and in some cases complained about not being able to find densities for the origin evaluation.
  - Canonicalize the inactive and virtual spaces of AVAS guesses, to avoid spurious warnings about core orbitals in the following CASSCF calculation.
  - AVAS: fixed wrong number of occupied orbitals in case no occupied orbitals should have been selected.
  - TRAH-CASSCF: compute generalized Fock matrix which is needed for the CASSCF nuclear gradient.
  - Fixed redundant generation of coupling coefficients in the CI guess.
  - Fixed ABS/CD spectra in calculation with !UseSym and QD-NEVPT2: The wrong densities were picked for the CASSCF transition moments.
  - Fixed ABS/CD when the NEVPT/QD-NEVPT2 ground state differs from CASSCF. Respecitve transition were missing.
  - Fixed MCD spectra not using transition densities from QD-NEVPT2 for the flag `DoFullSemiclassical=true`.
  - Updated manual: Reported `D4TPre` are updated to the new default value 1e-12. ORCA 5 used `D4TPre=1e-10`.
  - Fixed closed-shell case, e.g. CAS(6,3), crashing in NEVPT2.
  - Fixed NEVPT2/FIC-NEVPT2 wrong energies or crashing for the Vija class to wrong addressing.
  - Fixed ICE densities not stored in density container.
#### ANISO
  - Fixed T and L matrices passed to the single-aniso.
  - Fixed wrong number of non-relativistic states passed to single-aniso.
#### QDPT
  - Corrected QDPT transition density for excitations beyond "none".
  - Information added to QDPT AMatrix.
  - Issues in QDPT properties in `orca_lft` have been addressed.
#### QM/MM
  - Speed issue for QMMM optimizations.
  - Crystal-QMMM and compound crashed.
  - Removed leftover files from QMMM-IRC amd QMMM-NEB.
#### Relativity
  - Crash for F12 + X2C/ZORA/DKH.
  - Unnecessary abort in AutoCI gradients with X2C/DKH/ZORA.
  - Disabled X2C+GIAO+FiniteNuc (not yet implemented).
  - 2nd-order PC correction to DKH gDSO now skipped when `fpFWtrafo==false` due to numerical instability.
#### Solvation
  - Disabled analytical gradient and Hessian for XTB calculations requesting CPCMX (not implemented).
  - FINAL SINGLE POINT ENERGY for calculations requesting CPCMX was wrong.
  - Crash for calculations requesting Freq + CPCM + dummy atoms.
  - Crash for QM/QM2 calculations with CPCM requesting excited states.
  - Crash for multiple XYZ File Scans for DRACO.
  - Crash with CPCM + NoIter + Pal + open-shell.
  - Fix for GC and CPCM. 
#### Optimization
  - Multi-XYZ optimization crash.
  - Random possible break when using GFN-xTB Hessian.
  - Random crashes for `RECALC_HESS=TRUE`.
  - COPT was saving wrong Cartesian Hessian under certain conditions, would break.
  - Maximum number of angles that can be included is fixed + better error message.
  - Analytic Hessian as initial Hessian option crashed with IRC.
  - Crash in NEB-TS with subsequent Hessian, caused by change of number of parallel processes for NEB (max 32).
  - NEB parallelization (will - again - automatically start in parallel, if enough processes are available).
#### GOAT
  - GOAT/DOCKER/SOLVATOR now running on Windows.
  - WorkerRandomStart fixed and working as intended.
  - `-REACT` and `-EXPLORE` were (by mistake) not included sqrt(NFrag) to number of opts.
  - Missing timings for GOAT.
#### DOCKER
  - Abort if all final optimizations fail, was ending normally.
  - Do not switch to COPT if constraints are given.
#### Stability analysis
  - Stability analysis + closed-shell systems + post-processing (Hirshfeld, NBO, ...).
  - `SkipSecondSTAB` was still checking for energy differences between steps. Now will move on regardless.
#### `orca_2json`
  - Exported relativistic integrals were wrong in, HMO and angular momentum were missing.
  - Choice of origin corrected.
  - Empty `[]` and `[""]` are no longer crashing but disabling the options.
  - Invalid property JSON syntax in the following cases:
    - multiple geometries (e.g. optimizations);
    - some jobs with multiple properties of the same kind;
    - CIPSI energies;
    - MDCI EOM energies;
    - XTB jobs;
    - energy extrapolation.
#### `orca_mapspc`
  -  XAS/XES broadening functions satisfy FWHM.
  -  Adjusted .stk files normalization to report band integrals.
#### Compound
  - MORead with same type and number of atoms but different arrangement.
  - Bugs in statistical functions.
#### Miscellaneous
  - SOMF(1X) parallel bug in semi-numeric Coulomb.
  - Dummy/ghost atoms lead to crash in Hessian (partial fix).
  - Fixed bug of Fermi smearing calculations of two-electron systems.
  - Hangup in `leanscf_aftermath` when using F12 and ECPs.
  - Issues in RIXSSOC, XESSOC spectra in ROCIS have been addressed.
  - Issues in computing RI-SSC Integrals have been addressed. This property is now turned on in CASSCF, LFT and MRCI modules.
  - Fixed a crash in MD and L-OPT when the input file name was "orca".
  - Default COSX algorithm is set to AUTO everywhere, as originally intended.
  - Disable frozen-core approximation when no frozen-core electrons are present.
  - `orca_vib` was not able to read hess file from AnFreq run.
  - For very small systems restart Hessian could crash.
  - Small deviations between the Guess CI Matrix and the Sigma Vector in GS-ROCIS.
  - DCD-CAS: Removed left-over files.
  - Uncontracted MRCI: Fixed partial general contraction calls in the MRCI integral transformation (crashed before).
  - Crash for geometry optimization followed by a vibrational frequency calculation with fixed point group Ci.
  - Removal of `posix_memalign`, due to glibc/kernel bug.
  - NBO communication fixed.
  - Fixes a crash in the integral transformation.
  - Crash in `orca_vpot` due to missing prescreening matrix.

### Improvements

#### Output
  - Print all orbital energies for `!PrintMOs` and `!LargePrint`.
  - Removed redundant warning when using gCP for elements Z > 36 (Kr).
  - Added citations for wr2SCAN and DFT-D4 extension.
  - Better printing of the spin coupling situation of the states resulting from GS-ROCIS calculations.
  - Prepended a counter to irrep labels when printing vibrational frequencies.
#### `orca_2json`
  - Citations added to json output file.
  - Absolute path in basename possible.
#### `orca_mapspc`
  - Added support for VCD, XASSOCV and XESSOCV spectrum processing.
#### Symmetry
  - Ensured correctness of gradient cleanup, geometry optimizations with fixed point groups and calculations of vibrational frequencies  (for point groups with real irreps using pure Hartree-Fock).
  - Ensured correctness of the petite-list algorithm for SCF energy and gradient.
#### Compound
  - Implemented automatic knowledge of basenames.
  - Added GOAT interface.
#### Miscellaneous
  - Added ASCII checker to input file.
  - Add the possibility to read multi-XYZ files with no '>'.
  - QDPT in CASSCF now uses the magnetic origin as defined in `%eprnmr` (if not set, defaults to CenterOfNucCharge for backwards compatibility).
  - Reduced disk usage and optimized performance for CASSCF (transition) densities in density container.
  - Keep topology in initial IDPP path generation.
  - Add CIS Gradient in property file.






## Changes ORCA 6.0.0

### SCF and Infrastructure

- Significant improvements to the SOSCF solver to make it more robust, preventing huge steps that break the SCF. Overall improvements on the DIIS solvers.
- Due to the SCF updates, the AutoTRAH is now not so often needed and will start now only from above 50 cycles (`AutoTRAHIter`).
- Improvements to the memory handling of TD-DFT, CP-SCF and the Hessian

### Basis sets

- def-TZVP and ma-def-TZVP pseudo-potential basis sets for the actinides (Z = 89, Ac - 103, Lr)
- Lehtola's hydrogenic gaussian basis set family (HGBS) including polarized (HGBSP) and augmented (AHGBS, AHGBSP) variants for all elements up to Oganesson (Z = 118)
- def2-SVPD, def2-TZVPD, def2-TZVPPD, def2-QZVPD, def2-QZVPPD basis sets for lanthanoids
- vDZP Grimme's double-zeta valence basis set
- `!MINIX` now correctly activates the corresponding ECP
- Added user-specified L-limit to AutoAux `AutoAuxLLimit`
- Fixed segfault in dhf-ECP
- Fix for `DelECP` in `%coords`
- Added `ReadFragBasis` keywords read fragment-specific basis sets from a file

### Solvation

- New charge correction / compensation algorithm (corrected charges printed in an additional file)
- C-PCM/B scheme for QM/MM calculations
- DDCOSMO and CPCM/X available for XTB calculations and QM/MM calculations
- Generalization of names within all solvation models (C-PCM/SMD/ALPB/DDCOSMO/CPCM-X)
- New discretization scheme for the cavity (C-PCM) based on a constant number of charges per unit of area
 
### DFT

- Allow LibXC functional customization via external parameters
- Simple input keywords added for some LibXC functionals
- Added wB97M(2) functional parameters: must be used with wB97M-V orbitals in a two-step job (compound script available)
- D4 for elements 87 (Fr) - 103 (Lr)
- r2SCAN-3c extension to elements 87 (Fr) - 103 (Lr)
- Simple input keyword for functionals with revised D4 parameters by Grimme (wB97X-D4rev, wB97M-D4rev)
- New hybrid functionals: r2SCANh, r2SCAN0, r2SCAN50, wr2SCAN, wB97X-3c
- New double-hybrid functionals: Pr2SCAN50, Pr2SCAN69, wPr2SCAN50, kPr2SCAN50
- Simple input keywords for 2021 variants of revDSD-PBEP86-D4 and revDOD-PBEP86-D4
- Bugfixes for LibXC combined `*_xc_*` functionals
- Fixed crash for D4 + ghost atoms

### Excited states

- Analytical gradient for meta-GGA functionals
- Small bugfix to spin-adapted triplets and NACMEs.
- The FolllowIRoot for excited state optimization uses now a much more robust algorithm.
- New implementation for UHF EOM-CCSD and STEOM-CCSD.
- Core ionization/excitation energies using UHF IP-EOM-CCSD and STEOM-CCSD. 

### Relativity

- Enabled `NumGrad` with relativistic methods
- Second order DKH picture-change correction of contact density
- Minor fixes in DKH picture-change corrections of magnetic properties
- Picture change corrections are activated automatically

### Multiscale

- Reading PDB files for 10k+ atoms with HETATMs now possible
- Enabled correct FlipSpin behavior with QMMM
- More efficient MM Module
- Implemented wall potential

### Coupled cluster / DLPNO

- Implemented energy ordering for PNO generation
- Added semicore treatment for DLPNO
- Enable DLPNO-CCSD(T) calculations to run DLPNO-CCSD unrelaxed densities

### MP2
- Corrected memory estimates and batching in response and gradient
- Removed the slow and limited analytic (RI-)MP2 Hessian code
- Removed non-default Gamma-in-core option for RI-MP2 response
- Disabled single-precision calculations
- Disabled SemiDirect option in AO-MP2
- Enabled range-separated DHDFT gradients with RIJDX

### NEB

- Improved IDPP initial path
- More efficient GFN-xTB runs for NEB

### COSX

- Improvements to numerical integration grids, both for DFT and COSX
- Faster grid step
- Improved performance and accuracy in COSX, also for the gradient and Hessian

### Properties

- NMR spin-spin coupling: 
  - Added `SpinSpinElemPairs` and `SpinSpinAtomPairs` keywords to limit which couplings are computed
  - Reduced the number of CP-SCF perturbations necessary via a stochastic selection 
  - DSO term was transposed.
  - Off-diagonal PSO elements had the wrong sign
  - Efficiency improvement: solve SD/FC CP-SCF equations in restricted mode for RHF, instead of always using UHF
- Optimized numeric integration for HFC gauge correction
- Removed `RITRAFO` option for CP-SCF
- Switched to `tau=Dobson` as default handling of the kinetic energy density in meta-GGA magnetic properties with GIAOs

### Hessian

- Improvements to the Hessian to avoid accumulation on numerical noise and reduce the number of spurious negative frequencies.

### Geometry Optimization

- Several improvements to the geometry optimization, making is much more stable. Complete redesign of the Cartesian optimizer (!COPT), making it quick enough to be used together with faster methods.
- Fallbacks in the geometry optimization in case something fails, e.g. if the internal coordinates are unacceptable.
- Arbitrary spherical, ellipsoidal or box-like wall potentials can be added, which will reflect on the energy and gradients and can be used during geometry optimization.

### Miscellaneous

- CHELPG charges that reproduce the ESP together with the molecular dipole moment
- Fixed issues with constraints in multi-step jobs
- Molden output: store ECP info in `[Pseudo]` block, set point charge atomic number to 0, handling of ghost atoms
- Made the `ExtOpt` interface easier to use
- Store energy from NEB and IRC in the XYZ file