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castep_RELEASE_NOTES.txt CASTEP 16.1 (formerly 9.0) source distribution (Biovia release 2016) ================================= =============New functionality:

* OpenMP parallelism. Can now underpopulate multic ore nodes with MPI processes and use OpenMP multithreading to still efficiently use cores. This can be used to dramatically reduce memory re quirements.

CASTEP will use only 1 thread *unless* one of the environment variables CASTEP_NUM_THREADS or OMP_NUM_THREADS i s set to an integer greater than 1. The value of CASTEP_NUM_THREADS i s examined first with OMP_NUM_THREADS used only if CASTEP_NUM_THREADS i s not set. Setting the threads to 1 will cause Castep to work the sa me as it does now.

* Tkachenko's many-body dispersion method (SEDC_SC HEME=MBD/TSSCS). (Experimental first release - Use with caution.)

* Full release of non-collinear magnetism. New keyw ord SPIN_TREATMENT=NONE/SCALAR/VECTOR (+ aliases)

* Spin-orbit coupling. New param keyword SPIN_ORBIT _COUPLING. This can be used to compute Total Energy, Forces, Stress, Geometry Optimisation, Band Structure and Density of State s (using the spectral task). It requires spin_treatment = vector and j-depende nt pseudopotentials (available from ccpforge)

* Now reads fully relativistic pseudopotential file s in .uspso format.

* Can now read ".UPF" format pseudopotential files, including GBRV and ONCVPSP libraries.

* Can now use %BLOCK SPECIES_POT to specify pseudop otential library either per-element or for every element.

* New built-in library of norm-conserving pseudopot entials. ("NCP" library)

* The default "C9" USP pseudopotential library is a minor update of "C8" with improvements to Cr and Mn. This has a " Delta" precision of 0.5 meV - see https://molmod.ugent.be/deltacodesd ft

* "QC5" library of very soft ultrasoft potentials w ith KE filter parameter "qc=5". Should require a cutoff of 280 eV or less for most elements. This has a "Delta" of 1.4 meV, but is r elatively untested on real-world simulations. Use with caution.

* New "BREAK" keyword inside "%BLOCK *_KPOINT_PATH" allows specification of BS, PHONON etc k-space paths containing disconnec ted segments.

* More support for classical potential based MD sim ulations with new "pair_pot" module. See "Spec/pair_pot_doc.pdf".

* New tool "cellmerge" for manipulating and combini ng input cells. See "Doc/cellmerge/cellmerge_doc.pdf"

* New param %BLOCK XC_DEFINITION allows "roll-your- own" XC functionals. Use at your own risk!

For developers:

* Prototype version of Python/CASTEP interface.

Fixes:

castep_RELEASE_NOTES.txt* Units of Raman activity were incorrectly labelled in <= 8.0. Now in A**4/amu

* Raman tensor output was incorrectly scaled on out put due to units error. Now reported in sqrt(A/amu). Raman tensors from C ASTEP 8.0 and earlier have correct relative but incorrect absolute magnitude .

* Fixed rare phonon abort with "irreducible set is not a subset of full set." in case of highly skew cells.

* Improved reporting of memory requirements.

* ELF bug fix: previous versions were overly sensit ive to the charge density minimum.

Known issues:

* Band parallelism may not work with ultrasoft pseu dopotentials - geometry optimization or MD runs of larger system s (> 100 atoms) can abort unpredictably.

Notes: This release was formerly to be called 9.0, but was changed atrequest of Biovia marketing types.

==============================

CASTEP 8.0 source distribution ==============================

New functionality

* DFPT+D Phonons - linear response phonon calculati ons with dispersion correction.

* J-coupling with USPs and ZORA to include scalar r elativistic effects.

* Extended-Lagrangian Born-Oppenheimer molecular dy namics (XL-BOMD) with NVE andNVT ensembles.

* Symmetry analysis now done with Spglib (http://sp glib.sourceforge.net) for improved performance and stability over K290.

* Stability improvements to the on-the-fly (OTF) ps eudopotential generator.

* New default OTF pseudopotential strings, achievin g a Delta-value of 0.5 meV/atom (molmod.ugent.be/deltacodesdft).

* Band-parallelism for EDFT SCF minimiser.

* New WRITE_CHECKPOINT parameter to optionally supp ress checkpoint the files .check and .castep_bin. Useful for high-throughput.

Optimisations

* Mulliken population analysis

* Band-parallel electronic minimiser now uses async hronous communications in some places.

* Non-local Fock operator now only applies to bands with zero occupancy.

* Special handling of the non-local exchange operat or when the wavefunction thatdefines the

castep_RELEASE_NOTES.txt operator is the same as that to which operator is being applied.

* Improvements to dense matrix diagonalisation rout ines.

* Optimised application of Hubbard U.

Fixed bugs

* Raman tensors for degenerate modes now correctly includes all symmetry operations.

* Fixes for TPSD geometry optimisation.

* Fixed band-parallel fixed-occupancy geometry opti misation/MD crash.

External tools

* CASTEPconv by Simone Sturniolo - python scripts f or automated convergence testing of plane-wave cut-off and k-point sampling.

* Andrew Walker’s elastic constants scripts - pytho n scripts for generation of strain patterns and analysis of CASTEP calculations on those structur es to obtain elastic constants. (https://github.com/andreww/elastic-constants)

Miscellaneous

* New compile configurations for ifort 15 and GNU fortran 4.9 series;

updated GNU fortran 4.8, Sun, NAG builds; revised configurations for 32-bit

builds.

* Updated test suite with additional functionality tests and now tests the OTF pseudopotential generator by default.

* The DEVEL_CODE parameter is now a block - develop ers/advanced users will need to modify old param files using DEVEL_CODE.

* Experimental partial interface to libxc (http://www.tddft.org/programs/octopus/wiki/index.p hp/Libxc).

CASTEP 7.0.3 source distribution ================================Bugfix release,

* Corrected handling of vacuum space in spin-polari zed HSE calculations, avoiding divide-by-zero in |Grad s| /s term separately for each spin channel. Previously spin-polarized HSE calculations such as H atom in large box could give bad result s.

* Fixed bug in phonon supercell calculations which gave nonsense (large-amplitude oscillations in dispersion) in p honon dispersion in case of off-diagonal supercell matrix (a regressi on in 5.5).

* Fixed long-standing issue where some choices of c ell for interpolation or supercell phonon calculation cou ld give wrong results (large-amplitude oscillations in dispersi on) using "cumulant" fine method. This was seen in some fra ction of calculations with highly skew or acute cells, suc h as body-centred tetragonal (short c axis) with particular choices of cell vectors.

* Fixed logic error in phonon calculation driver: s ome continuations would restart from beginning due to incorrectly-d iagnosed

castep_RELEASE_NOTES.txt inconsistency between partial dynamical matrix an d Born charge data read from checkpoint.

* Fixed for incorrect results with the combination of supercell calculation using entirely norm-conserving pseudo potentials. Dipole tail correction term was being applied inconsiste ntly only to interpolated bynamical matrices if Born charges a nd permittivity had been calculated.

* Bug fix for ELF. Scales properly with cutoff ene rgy.

* Build system updates for Oracle PGI, and Cray com pilers

* Fix to output formatting in cell_write_cell which could overflow fixed-width field in %BLOCK species_gamma.

CASTEP 7.0.2 source distribution ================================Bugfix release,

* Fixed a severe bug in the implementation of sX-LD A with spin polarization. Previous spin-polarised sX-LDA cal culations should be considered suspect. (Eg in ferromagnetic MnO the energy changes from -3221.594 to -3214.604 eV). Spin unpolarised and other functionals are not affected.

* A couple of small bugfixes to non-collinear magne tism

* Fix bug in density_calculate_wvfn which caused ab ort in spin-polarised gamma-only case.

* Fixed close of file on non-root node in model_den sity_read which caused abort with ifort 14 MPI compile at - O1.

* Fix for parallel hang on continuation to a TDDFT calculation. Fixed a parallel bug in model when continuation i s from a TDDFT calculation.

* Fix for crash in DFT+D FD phonon calculation

* Fixed bug writing the .bands file in band-paralle l mode.

* Fixed bug and optimised performance of non-primit ive cell detection Performance optimisation of initial symmetry anal ysis for very large systems

* Postprocessing scripts update - Updated cteprouts for whitespace change in .cas tep format - Fixes for missing initial label and gnuplot dri ver in dispersion.pl and dos.pl - dispersion.pl auto detects .castep file correct ly even where +---...---+ is not first line

* Several fixes to and in support of "phonons" post processing utility Fixed parameters_reread when spectral_theory is m odified on continuation

* Updates to build system - ifort targets with FFTW3, now pick standalone F FTW over MKL emulation. - Portability fix for ACML version number routine - Support non-GNU versions of tar in "make dist" - tracebacks now work under MacOS/Darwin

CASTEP 7.0.1 source distribution ================================

castep_RELEASE_NOTES.txtBugfix release - a few items which arrived too late for 7.0

* Fixed a serious error in the implementation of sp in-polarised HSE functionals. (Spin-unpolarised HSE was fine) .

* Replaced built-in Cu OTF pseudopotential string. Original has a ghost state 0.5 eV below Fermi level in bul k Cu.

* Fixed segfault/crash on attempt at continuation w ith change of pseudopotentials.

* Updates to build configurations for Cray hosts. Added Intel compiler build configs for XC30 and updated Paths cale for 5.0.


New functionality

* Time-dependent density functional theory (TDDFT). Geometry optimisation and molecular dynamics of chosen exc ited state plus TDDFT excitation spectrum. Currently restricted to gam ma-point (vertical excitations).

* First development release of non-collinear magnet ism. This should be considered as experimental code for use by exp erienced modellers in collaboration with the developers. Please cont act Jonathan Yates or Daniel Jones if you wish to try it.

* Extended-Lagrangian Born-Oppenheimer molecular dy namics (XL-BOMD) [Steneteg, et al PRB (2010) 82, 075110 ]

* Atomic thermal displacement parameters (ADPs) fro m phonon calculations (thermodynamics task).

* Direct calculation of phonon DOS using adaptive b roadening for improved reproduction of arc features and singula rities.

* New tool "bs_sc2pc" contributed by Peter Brommer implements "effective band structure" agorithm of Popescu and Zunger PRB 85, 085201 for band structure unfolding in supercell calculations of defects and alloys.

* Bundled T. Bjorkmann's "cif2cell" program with re lease. From the database to input files in one easy step.

* Can now output density difference in formatted (. den_fmt) form.

Optimisations

* Electron density symmetrisation has been parallel ised to avoid performance bottleneck.

Fixed bugs

* SYMMETRY_GENERATE now handles non-primitive super cells correctly and generates the full set of space group operati ons for the simulation cell.

* Several fixes to LDA+U.

* Fixes for occasional problems with SHX2CELL and r elated scripts.

* Now honours FINE_GMAX param keyword which was ign ored in previous releases.

castep_RELEASE_NOTES.txt* Default OTF pseudopotentials should now work for all elements.

Miscellaneous

* Deprecated PHONON_SUM_RULE keyword in favour of PHONON_SUM_RULE_METHOD.

* Incomplete set of symmetry operations supplied in %BLOCK_SYMMETRY_OPS will be detected and flagged with a warning.

* New compile configurations for ifort versions 13 and 14, and revision of Pathscale and other build configurations.

* Command-line argument syntax revised to comply wi th GNU/POSIX conventions, eg "--search", "--help", "--dryrun". New "--version" command argument.

* Much-enhanced and more comprehensive regression t est suite.

* Can attatch text label to individual ions with "L ABEL=" tag to POSITIONS_FRAC/ABS data, eg for crystallographic site labels.


Fixed bugs

* "reuse" functionality did not work in 6.1, aborti ng with allocation error message.

* CASTEP now checks that supplied or generated symm etry operations form a group and aborts otherwise.

* Improved reproducibility of test suite bandstruct ure calculation Si2-bs.

* Fixed unassigned variable which caused crashes wi th some LDA+U supercell phonon calculations if built using GNU fortran.

* Fixed error reading SHELXL (.res) files in ctepro uts tools suite.

* Fixed a few minor precision errors which have no known consequences.

* Fix for an LDA+U stress error reported by Accelry s.

* Fix from David Quigley for stack memory overflow/ segmentation fault with largegrids .

* Improved checkpoint timing logic in phonon calcul ations.

* Added lock-out for case reported by Graeme Acklan d of Raman FD phonons with ultrasoft pseudopotentials which ran and produced output de spite not being implemented.

Porting:

* Updated build configuration for BG/Q - should now work out-of-the-box on Hartree Centre Blue Joule.


Feature Release

castep_RELEASE_NOTES.txt

New functionality in 6.1

* HSE xc functional now available (XC_FUNCTIONAL=HS E03/HSE06)

* New two point steepest descent geometry optimizat ion (GEOM_METHOD=TPSD)

* New "TASK = SPECTRAL" merging bandstructure, opti cs, EELS, DOS.

* New DOS/PDOS Joint DOS analysis tool for SPECTRAL calculations - OPTADOS http://www.optados.org/

* Band parallelism for FD phonon and exact exchange (incl. hybrid) XC functionals.

* Dipole corrections for slab/molecule calculations (new param keywords DIPOLE_CORRECTION and DIPOLE_DIR).

* New report on parallel efficiency at end of run.

Fixes and improvements

* Bugfix for OTF using XC_FUNCTIONAL=WC. Previous versions erroneously used LDA for unscreening of pseudopot ential when WC was specified. N.B. This will slightly chang e any results from OTF/WC calculations.

* Enhanced .cell file output with WRITE_CELL_STRUCT URE

* FIX_COM now defaults to FALSE if IONIC_CONSTRAINT S specified.

* HUBBARD_U values now changeable on continuation

* Robustness and performance enhancements to orbita l2bands tool.

* Optimized handling of degenerate modes in raman i ntensity calculation.

* Fixed bug where geom erroneously reported converg ed on 1st BFGS iteration.

* Fixed bugs in DAMPED_MD and DELOCALIZED geometry methods

* Fixed parallel bug with NUM_PROC_IN_SMP>0 for DFP T polarizability code.


Bugfix release:

* Fix for regression with aborts from magres tasks caused by convergence failure of "hamiltonian_diagonalise" .

* Moved some FFT grid arrays in magres_efg and mag res_hyperfine from automatic (stack) to allocatable (heap). This c ould cause crashes with some compilers especially when using FFTW v 3 as well as excess stack memory usage.

* Fix for crash for some efield and Raman calculat ions when using Sys V shared memory (num_proc_in smp > 1).

* Fix for error abort which printed stack traces t o multiple stderr outputs in parallel runs.

* Fix for regression with special point labelling in "dispersion.pl" band structure/phonon dispersion plotting script .


* Fix to "xxx2shx" conversion utility when writing SHELXL format files.

* Fix for regression in "orbitals2bands" band stru cture tool which failed completely in 6.0. Also includes stabilit y and performance improvements.

* Many fixes and updates to build system, to impro ve readability and robustness and to work in more cases than before , including fixes for some build architectures which contained bugs. N ow handles build and installation directory paths containing spac es. Now partially supports 64-bit Windows with Intel parallel comp oser. "Install" targets no longer perform unnecessary rebuild.

* Test suite now works in presence of directory pa th names containing spaces.

CASTEP 6.0 UKCP distribution ============================

Feature release

New functionality in 6.0

* DFPT phonon calculations extended to metallic sy stems. New DFPT solvers using self-consistent Green fun ction (Sternheimer equation) solvers. (Parameters pho non_dfpt_method and efield_dfpt_method),

* FD/Supercell phonons with LDA+U Hamiltonian.

* New task "spectral" which combines bandstructure , optics, elnes calculations, and postprocessing/plotting tool " optados".

* Raman spectra: New parameters "raman_range_low" and "raman_range_high" to restrict frequency range and compute partial spe ctrum. Now also prints depolarisation ratio.

* New options to print dynamical matrices or force constant matrices. PHONON_WRITE_DYNAMICAL and PHONON_WRITE_FORCE_CONSTANTS.

* Extended the coverage of the periodic table in D FT+D

* New conversion tool den2cube which converts from formatted density file <seed>.den_fmt into Gaussian Cube for use with Bader AIM analys is (http://theory.cm.utexas.edu/vtsttools/bader/) (existing tool castep2cube converts from binary checkpoint data).

* (beta) Electrostatic dipole correction (Yeh & Be rkowitz J.Chem.Phys 111, 3155-3162 (1999) and Neugebauer & Scheffler PRB 46, 16067- 16080 (1992).)

* (beta) Support for thermal conductivity calculat ions from MD. (J. Chem. Phys.106 6082 (1997)) Activate by parameter

devel_code : MD:TCOND :ENDMD

Specify swap interval by adding "SWAP=n", #slices by "Nslices=n" and gradient direction by "DIR=X/Y/Z" inside MD: :ENDMD in devel_code.

* (beta) Experimental interface to PLUMED Free Ene rgy/metadynamics library http://www.plumed-code.org/. To activate compile


make USE_PLUMED=yes

or add "export USE_PLUMED=yes" to the top -level Makefile.

Performance enhancements (6.0 also includes those d ocumented in 5.5.2)

* Low-memory LBFGS algorithm for geometry optimisa tion of very large systems.

* Lowered memory requirements for preconditioning and in PAW routines.

* Much better performance generating very large Mo nkhorst-Pack k-point grids.

* New preconditioner for DFPT calculations "phonon _preconditioner=HR"

Bugs fixed

* Several bug fixes to band-parallel calculation.

* Electric field response calculations gave incorr ect results for permittivity and Born charges if additional bands were specified (nextra_bands > 0).

* Fixed incorrect sign of forces bug under externa l electric field ("%BLOCK external_efield" in .cell)

* Density_symmetrise - fixed grid edge point bug w hich changed energies slightly with underconverged grids.

Miscellaneous

* Writes a new file "<seed>.bib" at end of run con taining citations for methodsused.

* Interface scripts provided to use CASTEP in conj unction with ATAT http://www.its.caltech.edu/~avdw/atat

CASTEP 5.5.2 UKCP distribution ==============================

Bugfix and optimization release.

New Feature:

* MD with new Hoover-Langevin thermostat [J. Stat. Phys. v135 261-277 (2009)]

Compilation and installation

* Build system updated with settings for more recen t compiler versions

* Build system revised for better error reporting a nd more robust behaviour, removing some superfluous and hard to understand incidental diagnostic output.

* First release of post-build regression test suite , based on James Spencer's "testcode" (http://www.cmth.ph.ic.ac.uk/people/j. spencer/code.php). Requires python to run.

Use build command "make check" to run. Finer-grained testing can be enabled fro m the Makefile in the "Test" subdirectory.

castep_RELEASE_NOTES.txt Note that the bandstructure run "Si2-bs" will fa il in k-point or mixed parallel because of different output formats and the geom etry optimization tests "TiO2-geom" and "MgCl2-geom" may fail because of slightly di fferent numerical results in the output.

Bugfixes:

* Fix for LDA+U where occupancy matrix was not bein g correctly updated.

* Fixed some bugs with allbands and EDFT methods wh ere extra bands are present.

* Several bugs with band-parallelism are fixed

* Fixed MD bug where DAMPEDMD method was not recogn ised.

* Fixed potential crash on Raman intensity calculat ion.

* Don't abort if phonon group theory analysis fails - just print "?".

* DFPT Phonon and efield calculations with addition al bands now work correctly. 5.5.1 and earlier gave wrong results for Born cha rges and permittivity if nextra_bands > 0

* Changed tolerances to work around numerical insta bility in B88 exchange potential where density is very small.

* Fixed bug in SMEARING_SCHEME=HERMITE_POLYNOMIALS where -ve occupancies were not allowed.

* Minor/trivial bugfixes to DFT+D output, phonon su percell w/o symmetry, phonon gamma directions

Parallel performance enhancements:

* Much improved performance of wavefunction, densit y and potential read and write to and from checkpoint files by use of MPI collectives. * Considerably enhanced performance of shared-memor y optimizations which now use System V shared memory. Activate by

num_proc_in_smp=N

in param file where N is >= the number of process ors/cores accessing a shared memory node. This should allow more G-v ector parallelism before performance gains are lost.

WARNING: Requires compiler which supports Fortran 2003 C interoperability in the ISO_C_BINDING intrinsic module, which all modern Fortran compilers support. But the use constitutes a step -up in CA STEP's language requirement it is likely that some older installations which succeed for CASTEP 5.5.1 will fail to compile 5.5.2. As there are now 5 f ree ("of charge" and "Libre") Fortran compilers available this should not be an impediment.

This optimization may be turned off to allow comp ilation with an earler compiler by uncommenting the line "NOSYSV := true" in the top level makefile.

* The algorithm to choose the best "mixed" k-point/ G-vector parallel distribution has been improved to make maximum use of k-point parallelism by leaving some

castep_RELEASE_NOTES.txt nodes idle. This should help overcome the proble m of all previous releases that some calculations would run very inefficiently (u sing too large a G-vector group) except on certain "magic numbers" of processors - a multiple of or having high common factors with the numbers of k-points.


Bugfix release

* Fix to CCPForge bug #419; DFT+D gives inconsistent results

* Fix to bug which computed degrees of freedom inco rrectly with nonlinear constraints and could give wrong t emperature for thermostatted, nonlinear constrained MD.

* Fixed a very longstanding bug in basis which coul d underestimate size of array and give bounds error or crash in r are circumstances.

CASTEP 5.5 UKCP distribution ==============================

* Band parallelism. Added new layer of parallel di stribution over bands. Activate by "devel_code bandpar=4" to use 4-way b and parallelism. Recommended values are in range 1-8. Supported f or SPE, Geometry, MD tasks so far. Only for local and semilocal DFT in this release (not hybrid exchange and LDA+U).

* Semi-empiricial dispersion correction (DFT+D) add s disperion forces for SPE, Geom Opt, MD, FD/supercell (not D FPT) phonons.

* New FIRE method for geometry optimization [PRL 97 , 170201 (2006)]

* PIMD in the NPT ensemble (Langevin only)

* Improvements to PIMD including new initialisation algorithm for faster convergence

* Can now output finite-T pressure tensor periodica lly throughout MD run.

* Hirshfeld population analysis extended to perform spin analysis

* More flexible dynamically-adapting parallelism fo r phonon calculations allows larger and more flexible processor counts by leaving some nodes idle.

* Several important memory-saving optimizations for distributed parallel running on large systems, particularly those cont aining transition metals.

* Added option to write optimised final structure a s new .cell or .cif file (parameters WRITE_CELL_STRUCTURE and W RITE_CIF_STRUCTURE).

* Enhanced thermodynamics output from lattice dynam ics/thermodynamics module. Now tablulates E, S, Cv also calculated as well a s F.

* B3LYP hybrid functional corrected. (Previous rel eases contained erroneous implementation and generated incorrect results).

* More consistency checks in build system. Platform support for MacOS/X enhanced with support for 32/64 bit and gfortran compilers.

castep_RELEASE_NOTES.txt* Performance optimisation for EDFT.

* Many other performance optimizations, robustness enhancements and bug fixes.


* Bugfixes to symmetry handling for phonon calculat ions, and other minor fixes. Removed spurious warning of out-of-c ell atoms for polarizabilility and Raman calculations.

* Fix for unassigned variable error if no nonlocal projectors.

* Fix for memory alignment bug with FFTW3/Pathscale library/compiler

* Updates to build configurations, particularly for Cray XT, Pathscale, gfortran and XLF targets. Added Open64 compiler.

* Memory optimizations for massively parallel use.

* Bugfix for task farming which was broken in 5.0.1

CASTEP 5.0.1 UKCP distribution ==============================* Performance improvements, mostly for Gamma-point mode.

* New experimental feature for phonon calculations. Better efficiency using mixed gv/k-point parallelisation by choice of num bers of nodes to use on a per-perturbation basis. (A few nodes may be lef t idle.)

Activated using

devel_code : PHONON_IDLE_NODES

* Fix for rare bug in phonon symmetry analysis code .


* New functionality

- Hirshfeld population analysis

- New PBEsol XC functional

- Stress calculation and cell optimization with sc reened exchange functional

- New Magres capabilities

= EPR Hyperfine Interaction Tensors

= Electric field gradient tensors for spin-polar ised systems

- Phonon capabilities

= IUPAC (Mulliken) mode labels for irreducible r epresentations in group theory analysis

= Finite displacement phonon calculations with n onlocal Sx, B3LYP, PBE0 and HF functionals.

- EELS/ELNES can now calculate spectra with d-hole s.

* Enhancements


- Much lower memory requirement for massively para llel runs by distributing <beta|phi> coefficients across processors (previously repli cated data). ("Packed and Distributed beta-phi")

- EFG Values of the nuclear quadrupole moments have been updated according to "Year-2008 Standard Values of Nuclear Quadr upole Moments: P.

� Pyykk , Mol. Phys. 106, 1965-1974 (2008)." As a result of using the updated values the reported Cq may differ slig htly from versions of castep prior to 5.0. To obtain the old values you can set the value of Q in the cell file using %block species_q

- Vibrational Spectroscopy enhancements

= Full release of raman intensity

= Thermodynamics runs now allowed as continuatio n of standard (not just fine)DOS calculation

= Updated spectroscopic plotting and analysis to ols. (Raman modelling, gnuplot output).

= New assistant "phonon_kpoints" for suggesting good processor counts for efficient highly parallel phonon runs.

= Continuation/restart of FD/Supercell calculati on now reuses result of unperturbed supercell SCF now stored in ".fd_wvfn" file.

= Bug fixes and algorithmic performance enhancem ents which facilitate very large phonon calculations

= Performance improvements and optimisations to FD/supercell and DFPT phonons.

= New keyword PHONON_FINE_CUTOFF_METHOD to choos e supercell/interpolation force constant handling: Values are SPHERICAL or CUM ULANT for Parlinski "cumulant" method. This replaces PHONON_FORCE_CONSTANT_ELLIPSOID.

- Better symmetry handling:

= New keyword "snap_to_symmetry" adjusts input g eometry to enforce symmetry to high precision.

= Now generates symmetry-optimal cell vector ori entations for primitive cellsspecified using %BLOCK LATTICE_ABC.

= "Symmetry_generate" keyword now finds full sym metry in many more cases using %BLOCK LATTICE_ABC

* Various bug fixes - Improvements to input checking and error reporti ng - Fixes for ELNES from p and d states. - LDA+U total energies and forces.

castep_RELEASE_NOTES.txt CASTEP 4.4 UKCP distribution ============================

* New functionality

- Beta release of raman intensity calculation

[ With "TASK : PHONON" new parameter "CALCULATE_ RAMAN : TRUE" turns on raman activity calculation]

- BLYP and B3LYP full release.

[ Activate via parameter "XC_FUNCTIONAL : BLYP o r B3LYP ]

- Calculation of stress for exact exchange and hyb rid functionals

[ Activate with parameter "CALCULATE_STRESS : tr ue" or variable cell geom/MD.]

- CML output (optional part of build if FoX librar ies available)

[Select CML=fox in top level Makefile when compi ling.]

* Enhancements

- Gamma-point only calculations speeded up using i nversion symmetry properties at k=0 "real wavefunctions". Gives a factor of 2 improv ement for large calculations.

[No user action to activate needed - gamma-point calculation detected automatically]

- 2D electrostatic correction for slab models of a surface, including polar surface (Scheme of In-Chul Yeh and Max L. Berkowitz, J. Chem. Phys. 111, 3155 (1999);

DOI:10.1063/1.479595)

[activate with "devel_code=EWALD:EW3DC=T:ENDEWAL D" ]

- Improvements to phonon calculations = New wavefunction extrapolation scheme for FD p honon (incl supercell) calculations to reduce number of SCF cycles needed.

= Improved force-constant matrix cutoff algorith m using "minimum image" + boundary cutoff. Better convergence with supercell size, and mu ch better handling of anisotropic supercells.

[ new parameter PHONON_FORCE_CONSTANT_ELLIPSOI D=1.0 ]

= Real-space enforcement of phonon acoustic sum rule - handles 2d sheet meterials (eg graphene/graphite) correctly.

[ new parameter PHONON_SUM_RULE_METHOD = RECIP / REAL / REAL-RECIP ]

= Better automatic setting of convergence tolera nces when task changed to oneof phonon group on continuation.

= New phonon postprocessing tool "phonons" for c ustomization, isotopic substitution etc.

castep_RELEASE_NOTES.txt [ Set up .cell and .param as for new CASTEP ru n and invoke in similar manner ]

- Can use fft prime factors higher than 5 if FFT l ibrary supports it.

[ new parameter FFT_MAX_PRIME_FACTOR=n ]

- Enhancements to band structure/dispersion curve plotting tools dispersion.pl/dos.pl

[ dos.pl will now compile ir spectrum. New flag "-symmetry fcc/bcc/cubic/orthorhmombic/.... to dispersion.pl recognised high-symmetry poin ts in BZ and labels accordingly.]


* New functionality

- ELNES - Calculate Electron and X-Ray core-level spectroscopy

- ELF - Electron localisation functions ( Becke and Edgecombe J.Chem.Phys. vol 92, 5397 (1990))

- LDA+U

- PBE0 : New hybrid DFT/HF functionals

* Improved functionality

- Checkpoint/save and restart functionality added for bandstructure and magres runs.

- Performance optimisation for NMR chemical shift response calculations

- Performance optimisation for phonon DFPT calcula tions. Improved preconditioner

- New trial anisotropic cutoff scheme for Fourier interpolation and supercell phonon calculations.

* New Tools

- orbitals2bands : Band-structure plotting tool - detects crossings for correct BS plots with "dispersion.pl"

* Enhancements to many tools including dos.pl/dispe rsion.pl, file format conversion tools in cteprouts.

CASTEP 4.2 UKCP distribution ============================* New functionality

- Block-Davidson SCF solver is now the default.

- SMP adapted comms is now in mainstream code. Us e parameters NUM_PROC_IN_SMP (and ..._FINE) to use this mod e for mixed SMP.networked parallel clusters.

* Improved functionality

- MD with nonlinear constraints.

castep_RELEASE_NOTES.txt - Both Berendsen thermostat AND barostat are now implemented.

- Variable cell geometry optimisation under aniso tropic external stress now works with symmetry turned on provided stre ss is compatible with symmetry.

- Improved elastic constants analysis within BFGS geom opt

- Constrained lattice dynamics calculations (a.k. a. partial Hessian)

- Phonon group theory analysis is more robust.

- Phonon group theory analysis now flags IR and R aman activity of modes.

- Phonon DFPT now works with pseudopotentials inc luding core charge density and implements non-linear core correcti on. (Core-charge pseudopotentials may be generated using the built in OTF generator or using OPIUM via updated version 3 .6 .recpot format.)

- DFPT phonon calculations should be much faster at OPT_STRATEGY=DEFAULT and use less memory (improvements to paging str ategy.)

- Improvements to default tolerances for phonon c alculations.

- FIXED_NPW=.false. is now default for variable-c ell geometry optimization andMD calculations.

* New Tools

- cube_tools from Jorg Meyer, FHI: Tools for conve rting CASTEP charge densitiesinto Gaussian CUBE and Xcrysden formats for visualisa tion and analysis.

- mode_follow: Analyse a phonon calculation and cr eate new .cell files perturbed by eigenvectors of selected modes. Useful for P E scans along mode or ceating sequence of files for animation - Symmetry_snap.f90: Read an input .cell file and adjust so that that all symmetries (explicit or automatic) are sati sfied to high precision.

CASTEP 4.1 UKCP distribution ============================* New functionality: - NMR Chemical shifts

- Electric Field gradients at nuclei

- Wu and Cohen GGA (WC) - Group theory analysis of phonon eigenvectors.

- New task THERMODYNAMICS calculates vibrational f ree energy from phonon fine DOS.

- New cell keyword EXTERNAL_EFIELD allows applicat ion of finite electric field (Sawtooth potential) for molecula r/slab systems. (NOT CRYSTALS)

- Ability to calculate dipole of isolated molecule via "calc_molecular_dipole" parameter

- Self-consistent pseudopotentials for all-electro n calculations


- New weak-coupling Berendsen thermostat

- Numbers of electrons can now be non-integer.

- New parameter elec_force_tol specifies convergen ce criterion on forces for SCF cycles

- Interface to OPIUM norm-conserving PP database & Bennett and Rappe nc PSP library.

- Nonlinear constraints added in internal co-ordin ates geom. opt.

- Can now write formatted charge density and local potential.

* Improved Functionality

- Block-Davidson SCF solver is now significantly faster than old. (Activate via "devel_code new_dm")

- New database of ultrasoft pseudopotentials.

- New CELL modifier SPIN to set initial atomic s pin. (replaces MAGMOM with more sensible units, ie s pin density)

- Improved user-friendliness of many error messag es.

- Efield calculation of ionic permittivity now wa rns and refuses to calculate junk in case of small or imaginary fr equencies.

- Improved performance and robustness of DFPT pho nons.

* Many bugs fixed, including

- Sutble phase error bug in phonon linear respons e which gave wrong results in rare cases.

- Removed several stack-allocated arrays which co uld cause a crash for machines with small stack sizes.

- Several continuation problems fixed.

CASTEP 4.01 UKCP distribution ==============================* New functionality:

- Fourier interpolation of dynamical matrices ove r the BZ for much faster DFPT lattice dynamics calculations of phonon dispers ion and DOS.

- Finite displacement and supercell method for la ttice dynamics of metallic systems, ultrasoft pseudopotentials.

- New interface to FFTW version 3. This is the f astest known FFT and give significant performance improvements.


- New preconditioning scheme improved.

- Build system updates. Now only need to edit bi n/arch to add new platform and add new flags file in "obj/platfor ms" to port to new platform.

* Many bugs fixed, including


- Nasty but rare error in DFPT phonon calculation s where off-diagonal elements of dynamical matrix could be miscomputed in cases of "intermediate" complexity with symmetr y. (Only seen in a-quartz so far).

- Parallel hangs when writing wavefunctions to ch eck file. (Previous implementation could overload buffer space in s ome MPI implementations.)

CASTEP 4.0 UKCP distribution ==============================* New functionality:

- Wannier Functions

- Infra-red intensities calculated for LR phonon at gamma point.

- Frequency-dependent dielectric permittivity (in IR range)

- Spin-dependent initial density for density-mixi ng method. Allows specification of initial spin states.

- Path-integral molecular dynamics.


- Re-implementation of exact exchange functionals . Runs up to 10x faster (butstill much slower than DFT)

- Adaptive kpoint/g-vector parallelism for MPP ph onon calculations.

- Finite-displacement phonon calculations now sav e partial checkpoints for crash restart.

- Very much faster M-P kpoint set generator.

- New Block-Davidson density-mixing solver (use " devel_code new_dm" to select)

- New preconditioner improves convergence with ul trasoft pseudopotentials. - Writing and reading .check files now much less resource-intensive. (Previous version could exhaust MPI buffer space for writ e and memory for read, leading to crashes)

* Many bugs fixed.

* New platforms added to build tree, notably Pathsc ale and g95 compilers.

CASTEP 3.2.1 UKCP distribution ==============================3.2.1 is mainly a maintenance release. New features compared to 3.1.1

* SCF: Improvements to EDFT

* SCF: Now prints E-0.5TS as well as internal and M ermin Free energy for a metal.

* SCF: Improved convergence in DM optimiser.

* Improved convergence tolerances for Ewald sums -- improves accuracy for non-orthogonal cells.

castep_RELEASE_NOTES.txt* Geometry optimizer: Cell constraints should fina lly work. Special cases of primitive f cc and bcc cells recognised.

* DFPT Phonons: Corrected missing term in 1st orde r GGA XC potentials which could cause inaccuracy or noise near or at Zon e-Boundary.

Fixed bug which could (in rare cir cumstances) give wrong outputby omitting large term in diagonal bl ock of dynamical matrix. (Usually gives ridiculous large imaginary a nd real frequencies.)

New regular output to indicate pro gress of calculation.

GGA results more robust in presenc e of (small) -ve electron density.

* General: Many bug fixes for parallel race c onditions and hangs.

Tightened up many tolerances for i nput reader. You need to specify lattice parameters, atomic co-ordi nates and symmetry operations

with an accuracy of 8 decimal plac es (in a.u.).

CASTEP 3.1.1 UKCP distribution ==============================New features compared to 3.02

* The Virtual Crystal Approximation allows the co nstruction of mixture atoms which can sometimes be useful for simulating disordere d systems. See L. Bellaiche, D. Vanderbilt, "Virtual crystal ap proximation revisited: Application to dielectric and piezoelectric properties of perov skites", Phys. Rev. B61 (2000) pp.7877-7782 * Charge-density differences output using new <>.param variable "calculate_densdiff".

* Variable cell-shape ("constant stress") molecula r dynamics.

* Geometry optimization with user-supplied cell co nstraints (%BLOCK cell_constraints) now works.

* "On the fly" pseudopotential generation. (This was actually present in 3.02 but not recommended.) If you omit the " %BLOCK SPECIES_POT" from the <>.cell file, CASTEP will not generate ultrasoft pseudopotentials using it's built-in generator program. Alternat ively a specification string may be given to tune the parameters and a djust the kind of pseudopotential produced, for example Al 2|2.2|5|7|15|30:31(qc)[3s2,3p2]

where the elements have the meaning

2 = local channel (d)

2.2 = rc (local, nl and rinner all at once)

5|7|15 = coarse|medium|fine (in Ha)

castep_RELEASE_NOTES.txt 30:31 = pseudise the 3s and 3p channels

(qc) = the pseudisation scheme (slightly experiment al, but seems good: tm is another option)

[3s2,3p2] = testing configuration

Documentation of this feature is still in prepar ation. For now an examination of the strings in the source code of ion_atom.F90 and a question to the CASTEP email list may help.

* Much better default parameter choice for density -functional perturbation-theory (DFPT) phonon and efield calculations. The resu lts of practical experience have been incorporated to set the tolerances and it s hould now be possible to perform a reasonably well-converged calculation with much less fiddling. (But don't take this for granted!).

Several performance optimizations to reduce CPU time and memory use of DFPT phonon calculations.

Bugfixes

* Better initialization for density-mixing in case of charged cells.

* Many, many bugfixes for parallel execution, avoi ding hangs and crashes on parallel machines.

CASTEP 3.02 UKCP distribution =============================

New Features (from 2.2)

* Built-in help facility. Try "castep -help"

* Ensemble Density Functional Theory; variational optimization

for metallic systems.

* New EXX (exact-exchange) functional for perform ing Hartree-Fock calculations. Several variants including S creened exchange.

* Electric Field linear response: DC and optical dielectric permittivity of insulators. Task: efield

* Born effective charges (with either of efield o r phonon tasks)

* Phonon linear response now includes LO-TO split ting terms (using the electric field response).

* Phonon linear response: many performance optimi zations including the ability to use symmetry-reduced k-point sets.

* Phonon linear response: GGA XC functionals now fully supported accurate results at any phonon q-vector.

* Enforcement of phonon Acoustic Sum Rule (parame ter PHONON_SUM_RULE)

* Transition-state searching using Accelrys' pate nted LST/QST algorithm.

castep_RELEASE_NOTES.txt * New geometry optimization method using internal co-ordinates for faster optimization of molecular system s.

* Geometry Optimization under applied external sh ear stress.

* New option FIXED_NPW for variable cell geometry optimization and molecular dynamics at fixed cutoff (var iable number of plane-waves).

* Variable cell (constant pressure) molecular dyn amics. * Nose-Hoover chains MD.

* Many bugs fixed. Particularly for parallel exe cution on cluster systems.

castep release notes - intranet home · castep_release_notes.txt operator is the same as that to...

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