Xtb

Feature release with new GPU acceleration, improved ALPB parameters, better optimizer settings and options, and general performance improvements for GFN1-xTB and GFN2-xTB.
Thanks to Sebastian Spicher (sespic), Marcel Müller (marcelmbn), Hagen Neugebauer (haneug), Thomas Rose (Thomas3R), Marcel Stahn (MtoLStoN), Julius Stückrath (jbstueckrath), Patrick Atkinson (patrickatkinson), Cyrille Lavigne (clavigne) and Igor Gerasimov (FulgurIgor) for contributing to this version.

- Bugfix: Basename detection failed for paths with path delimiter (https://github.com/grimme-lab/xtb/pull/362) :beetle:
- Bugfix: FOD flag (`--fod`) did not set electronic temperature correctly (https://github.com/grimme-lab/xtb/pull/382) :beetle:
- Bugfix: Sign error in unbiased hessian calculation (https://github.com/grimme-lab/xtb/pull/388) :beetle:
- Bugfix: IR intensities were calculated incorrectly from dipole gradients (https://github.com/grimme-lab/xtb/pull/395) :beetle:
- Bugfix: Fix out-of-bounds access for basis set in IPEA-xTB calculations (https://github.com/grimme-lab/xtb/pull/399) :beetle:
- Bugfix: Commandline interface for sequential build was inconsistent with OpenMP build (https://github.com/grimme-lab/xtb/pull/421) :beetle:
- Bugfix: Point charge embedding was not initialized correctly and skipped embedding calculations (https://github.com/grimme-lab/xtb/pull/422) :beetle:
- Bugfix: Negative charges were detected as command line flags (https://github.com/grimme-lab/xtb/pull/423) :beetle:
- Improved 2D to 3D conversion with GFN-FF (https://github.com/grimme-lab/xtb/pull/351)
- GPU version of xtb is available with Nvidia HPC SDK (https://github.com/grimme-lab/xtb/pull/342, https://github.com/grimme-lab/xtb/pull/352, https://github.com/grimme-lab/xtb/pull/407, https://github.com/grimme-lab/xtb/pull/420)
- Backports of performance improvements from GPU routines to CPU implementations (https://github.com/grimme-lab/xtb/pull/425)
- Allow adjusting of spring exponents in distance constraints (https://github.com/grimme-lab/xtb/pull/357)
- Allow scaling of dispersion energies / gradients for the GFN-FF (https://github.com/grimme-lab/xtb/pull/359)
- Improved ALPB implicit solvation parameters (https://github.com/grimme-lab/xtb/pull/372, https://github.com/grimme-lab/xtb/pull/387)
- Turbomole driver now attempts to cache results via gradient file (https://github.com/grimme-lab/xtb/pull/377)
- Adjusted optimization threshold for level “lax” for Turbomole DCOSMO-RS driver (https://github.com/grimme-lab/xtb/pull/383)
- Allow reading static RMSD bias from file (https://github.com/grimme-lab/xtb/pull/390)
- Use averaged convergence scheme in L-ANCopt and RF-ANCopt to deal with noisy energy surfaces (https://github.com/grimme-lab/xtb/pull/394)
- Refactored hessian implementation to stabilize build and allow higher compiler optimization (https://github.com/grimme-lab/xtb/pull/417)


[](https://github.com/grimme-lab/xtb/releases/download/v6.4.0/xtb-210201.tar.xz) [](https://github.com/grimme-lab/xtb/releases/download/v6.4.0/xtb-210201-oldkernel.tar.xz)

Maintenance and bugfix release.
Thanks to haneug, MtoLStoN, sespic, pprcht, Thomas3R, susilehtola and timostrunk for contributing to this version.

- ALPB solvation model has internal parameters now (new default)
- `--alpb`/`--gbsa` `gas`/`vac` will not enable the solvation model
- MTD can now use a static ensemble for RMSD bias as well
- MTD time constant can be adjusted from input
- MOPAC interface can now read dipole moments
- new `--bhess` runtype to get hessians on non-equilibrium structures
- Allow adjusting the imag. cutoff for thermo (`$thermo/imagthr=real`)
- Allow scaling of frequencies in thermo (`$thermo/scale=real`)
- Allow scaling of complete hessian (`$hess/scale=real`)
- `--json` flag to enable dumping `xtbout.json`
- Bugfix: Several workarounds for the NVIDIA compilers (former PGI) :beetle:
- Bugfix: Workaround GCC crashing on empty environment variables :beetle:
- Bugfix: Fixed non-deterministic failure of GFN-FF with GCC compilers :beetle:
- Bugfix: Charges are now handled correctly in PDB case :beetle:
- Bugfix: MOPAC interface reads total energy now from HEAT_OF_FORMATION :beetle:
- Bugfix: Fix error in GFN-FF torsion potential (new GFN-FF 1.0.2 version) :beetle:
- Bugfix: SDF input did not work with total charge in GFN-FF :beetle:

Maintenance and bugfix release. Many thanks to pprcht, susilehtola and felixmusil for contributing to this release.

- Bugfix: Reference occupations for GFN2-xTB were incorrect for d-block elements :beetle:
- Bugfix: CT file charges were not read correctly :beetle:
- Bugfix: The loader API functions for xTB parameters did ignore the optional parameter files :beetle:
- Bugfix: Wigner-Seitz cell generation was erroring on certain architectures :beetle:
- Bugfix: OMP parallelisation of Hessian was not working with solvation models :beetle:
- Bugfix: Turbomole gradient file is written with $gradient but should be $grad :beetle:
- updated metadynamics pathfinder
- ALPB model is now available
- Failed geometry optimizations are now rescued to perform a final diagnostic SP before stopping the xtb run

Maintenance and bugfix release.

- Bugfix: Total charge was not used in GFN-FF :beetle:
- Bugfix: Error handling in GBSA was not returned correctly :beetle:
- Bugfix: Copy mode overwrite of coordinate input :beetle:
- Bugfix: Negative charge was recognized as command line flag :beetle:
- Bugfix: Scan mode was not working correctly :beetle:
- Bugfix: GBSA energy was added twice for GFN-FF :beetle:
- Bugfix: Fix parallelisation issues in build (binary includes acf1ac7e1ac0e0c4bb98423fa3e7e44e812212be) :beetle:
- Logic for MKL linking has been reworked
- PGI Compiler is now supported for builds with meson
- Support for GCC 10.1 added

Please check version header for the correct version: 6.3.1-r1!

- periodic boundary conditions for GFN1-xTB Hamiltonians
- API support for periodic GFN1-xTB Hamiltonians (C, Python, ASE)
- general GFN Force Field (GFN-FF) for all elements up to Z=86
- 2D to 3D conversion of SDF input using the GFN-FF


This release is API compatible to version 6.2.2