Version 5 now available

[richard....@gmail.com]

Dear All,

I am very happy to announce that a new version of the VAMPIRE code is now available, incorporating a range of new features. From here on I do hope to be able to have an annual release cycle to make new features that have been tested more readily available to the community. A summary of the new features and changes is below. Also, the website has been updated with a new manual, and I hope to be able to add some oft-promised tutorials in the coming months.

https://vampire.york.ac.uk

All the best and Happy New Year to everyone!

Richard

Major new features

Improved dipole-dipole implementation using the dipole tensor (by Andrea Meo)

Implemented generic Dzyaloshinskii-Moriya interactions and Neel pair anisotropy

Beta CUDA and OpenCL acceleration (single card only) (by Oscar Arbalaez, Matt Ellis, Razvan Ababei, Sam Westmoreland and Sam Morris)

Support for parallel and binary I/O for supercomputing systems and ARCHER (Rory Pond)

New vampire data converter (vdc) utility for generating POVRAY/xyz files from spin configurations

Minor feature enhancements

Feature: Added initial support for non-magnetic atoms

Feature: Added implementation of ferromagnetic resonance fields and program with customizable field strength, frequency and direction

Feature: Added implementation of lateral and vertical temperature gradients

Feature: Added support for core-shell voronoi films

Feature: Added functions for creating random alloy distribution representing grain segregation of certain materials

Feature: Added shape factors to truncated octahedron generation code to allow elongated crystals

Feature: Added function to generate faceted nanoparticle with tunable 100,110 and 111 facets

Feature: Added Monte Carlo preconditioner to generate realistic spin state for thermalised LLG simulations

Feature: Added support for CSG operations with multi-atom unit cells

Feature: Added support for exponentially decaying exchange interactions

Feature: Added support for generic vectorial exchange interactions

Feature: Added 3D bubble-type crystallisation model with unable crystallisation radius

Feature: Added implementation of spin torque field

Feature: Added new archer target for makefile for compiling on ARCHER

Feature: Added option for rocksalt (NaCl) structure

Feature: Added support for precision control of magnetization data output with output:precision = and output:fixed-width input file flags

Feature: Implemented Neel anisotropy with site specific origin and pair wise constants

Feature: Implemented generic Dzyaloshinskii-Moriya interactions

Feature: Added capability for processing normalised exchange values from ucf files

Feature: Implemented working checkpoint feature for loop-based programs

Code Enhancements

Added support for double precision numbers of time steps, numbers of steps up to 10**12 and new limits for incremental variables to avoid infinite loops.

Added initial implementation of local uniaxial anisotropy fields

Added improved error reporting for seriously malformed material files

Improved error messages for reading unit cell file interaction list errors

Completed utility for generating framework files for new vampire modules

Changed default licence for new code to Free BSD

Added header timing function for more accurate timing of i/o routines

Removed warnings for missing variables and signed/unsigned comparisons and added debug option for llvm compiler

Removed deprecated C++ MPI bindings

Added vampire manual to source repository

Added function to calculate exchange fields and eliminated double negative in constant

Implemented parallelisation of exchange interaction verification and improved messages to log file

Added flag to enable bulk Neel pair anisotropy calculation

Modified parallel random number seeds to avoid correlation between different processor ranks for sequential seeds.

Made githash and version information available in info header, and added information to output and log files for easier reproducibility

Bugs squashed

Bugfix: fixed allowable time step increment to be 1 to prevent infinite loop

Bugfix: Changed input file reading of certain large numbers to use float by default with casting to int

Bugfix: Fixed Segmentation fault using global demagnetizing field calculation with new statistics calculation

Bugfix: Added missing implementation of spherical harmonics energy calculation for Monte Carlo simulations

Bugfix: fixed compilation of alloy.cpp on older compilers

Bugfix: fixed random crash in alloy code

Bugfix: moved small correction factor in crystal generation to small lattice offset to prevent duplicate atoms in large scale parallel simulations.

Bugfix: Corrected implementation of two temperature pulse calculations to include realistic pump power parameter (now specified in mJ/cm^2)

Bugfix: Added explicit required compiler support for c++11 for header file

Bugfix: Implemented fix from Joe Barker to cmc for materials with different moments to prevent small drift of direction of m

Bugfix: Fixed bugs in checkpoint restart for hysteresis and modified Curie temperature program in order to restarted from old temperature with checkpoint

Bugfix: fixed initialization bug found by cherishsir

Bugfix: now initializing material susceptibility with material magnetization

Bugfix: Added missing factor 0.5 in exchange energy calculation

Buxfix: Added 1/2 factor to magnetostatic energy

Bugfix: fixed sign error in 4th order cubic anisotropy and added comment in uniaxial field for clarity

Bugfix: Applied patch from Andrea Meo fixing Slonczewski field and parallel compilation error